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Formula-Backed Calculators

Browse finance, budget, tax, business, investing, math, economics, health, time & date, and home & energy calculators built with transparent formulas, interpreted results, and downloadable workbook support where useful.

Use the search and category filters below to find the right calculator for your decision — many tools include explanations, scenario comparisons, charts, and downloadable Excel workbooks.

181 calculators

FinanceMortgage CalculatorEstimate monthly payments, interest, taxes, insurance, PMI, and amortization using practical home-loan assumptions.Best for: Sizing up a home purchase before talking to a lender.FormulaXLSXChartsScenariosAmortizationAdvancedRegion modesOpen calculatorFinanceCompound Interest CalculatorSee how savings grow as interest earns interest, with adjustable contributions and compounding frequency.Best for: Understanding the long-run power of compounding.FormulaXLSXChartsOpen calculatorInvestingInvestment CalculatorProject lump-sum and regular-contribution growth, plan a goal, and solve future vs present value, with fees and inflation.Best for: Projecting how a lump sum or monthly contributions may grow, and the time value of money.FormulaXLSXChartsScenariosAdvancedOpen calculatorInvestingRegular Investment CalculatorProject how regular monthly contributions grow over time — SIP-style investing, dollar-cost averaging, inflation-adjusted value, and long-term goals.Best for: Monthly investing, SIP, and dollar-cost averaging.FormulaChartsOpen calculatorInvestingRetirement Withdrawal CalculatorEstimate how long savings last under regular withdrawals (SWP) — drawdown, safe withdrawal rate, inflation, and a year-by-year schedule.Best for: Retirement income, portfolio drawdown, and how long your money will last.FormulaXLSXChartsOpen calculatorMathStandard Deviation CalculatorSample and population standard deviation, plus variance, mean, median, quartiles, z-scores, outliers, and confidence intervals.Best for: Analysing the spread, shape, and outliers of a dataset, with every statistic at once.FormulaXLSXChartsScenariosOpen calculatorBusinessProfit Margin CalculatorWork out gross, contribution, operating, and net margin, with target pricing, break-even, scenarios, and SKU comparison.Best for: Knowing whether you are actually profitable — and where the margin leaks.FormulaXLSXScenariosAdvancedOpen calculatorTaxIncome Tax CalculatorEstimate income tax with custom progressive bands, a sourced US federal mode, refund or amount owed, and scenario comparison.Best for: Progressive tax, refund estimates, and take-home pay for any country.FormulaXLSXScenariosAdvancedRegion modesOpen calculatorFinanceLoan CalculatorWork out the monthly payment, total interest, and payoff date for any fixed-rate loan from the amount, rate, and term.Best for: A quick payment estimate for any kind of loan.FormulaXLSXAmortizationOpen calculatorBudget & CreditCredit Card Payoff CalculatorPlan up to 20 cards with issuer-style minimums, promo APRs, five payoff orders, and a balance-transfer scenario.Best for: Finding a payment that clears the cards and escaping the minimum-payment trap.FormulaXLSXScenariosOpen calculatorBusinessBreak-Even ROAS CalculatorWork out break-even and target ROAS from your real margins, plus max CAC, break-even MER, and ad budgets.Best for: Knowing the ROAS floor your margins demand — and the target that actually hits your profit goal.FormulaXLSXScenariosOpen calculatorTaxVAT/GST CalculatorAdd or remove VAT, GST, or HST from a price, solve tax-inclusive and tax-exclusive values, and build mixed-rate invoices.Best for: VAT, GST, and invoice tax breakdowns in any currency.FormulaXLSXRegion modesOpen calculatorFinanceMortgage Refinance CalculatorCompare your current mortgage to a new rate and term — monthly saving and break-even time on closing costs.Best for: Deciding whether refinancing is worth the closing costs.FormulaXLSXScenariosAmortizationOpen calculatorFinanceAmortization Schedule CalculatorBuild a full payment-by-payment schedule showing how each instalment splits between principal and interest.Best for: Seeing the year-by-year breakdown of any fixed loan.FormulaXLSXAmortizationOpen calculatorFinanceHome Affordability CalculatorEstimate the home price you can afford using the 28/36 debt-to-income rule on your income, debts, down payment, and rate.Best for: Finding a realistic price range before you start house hunting.FormulaChartsOpen calculatorFinancePersonal Loan CalculatorEstimate repayments on an unsecured personal loan and see how the rate and term change what you pay overall.Best for: Comparing personal-loan offers side by side.FormulaXLSXAmortizationOpen calculatorFinanceAuto Loan CalculatorCalculate a car-loan payment from price, down payment, trade-in, rate, and term, including the total cost of financing.Best for: Budgeting the monthly cost of a vehicle.FormulaXLSXAmortizationOpen calculatorFinanceCar Lease vs Buy CalculatorCompare ending wealth from leasing a car against buying it — monthly payment, car equity, and invested savings.Best for: Deciding whether to lease or finance your next vehicle.FormulaAmortizationScenariosOpen calculatorFinanceDebt Consolidation CalculatorCompare your existing debts against one new consolidation loan — monthly payment, payoff time, and total interest.Best for: Deciding whether a consolidation loan actually saves money.FormulaAmortizationScenariosOpen calculatorFinanceAPR CalculatorTurn a loan rate plus fees into the true annual percentage rate so you can compare offers on equal terms.Best for: Spotting the real cost behind a low headline rate.FormulaXLSXScenariosOpen calculatorFinanceInterest Ledger CalculatorSettle a private loan transaction by transaction — every advance, part-payment and rate change on its own date, under the day-count convention…Best for: Agreeing one number on a hand loan repaid in irregular lumps.FormulaXLSXScenariosAdvancedRegion modesOpen calculatorFinanceSavings CalculatorProject a savings balance or solve the deposit needed for a goal, with APR/APY, tax, and inflation.Best for: Forecasting savings growth or planning a savings goal.FormulaXLSXChartsOpen calculatorFinanceRetirement CalculatorProject your retirement pot from current savings, contributions, and growth, and gauge whether it meets your goal.Best for: Checking if your saving rate is on track.FormulaXLSXChartsOpen calculatorFinance401(k) CalculatorProject a 401(k) balance with employer match, 2026 IRS limits, fees, inflation, and a match maximiser.Best for: Maximising your match and projecting your balance.FormulaXLSXChartsAdvancedOpen calculatorFinanceCoast FIRE CalculatorFind the inflation-adjusted amount you need invested today to coast to your retirement target on growth alone — and the exact gap to get there.Best for: Checking if you can stop contributing and still hit your number.FormulaOpen calculatorFinanceBarista FIRE CalculatorFind the smaller corpus you need when part-time income covers part of your expenses, with a full-FIRE comparison and the gap to get there.Best for: Planning a semi-retirement where part-time work covers the rest.FormulaOpen calculatorFinanceGratuity CalculatorEstimate India gratuity payable from last drawn salary and years of service, using the 15/26 formula.Best for: India end-of-service gratuity under the Payment of Gratuity Act, 1972.FormulaOpen calculatorFinanceUAE Gratuity CalculatorEstimate UAE end-of-service gratuity from basic salary and years of service, using the 21/30-day MOHRE formula.Best for: UAE end-of-service gratuity under Federal Decree-Law No. 33 of 2021.FormulaOpen calculatorFinanceFreelancer vs Employee CalculatorFind the freelance hourly or day rate needed to match a target employee salary, after tax, benefits, and unbillable time.Best for: Pricing freelance rates against an equivalent full-time salary.FormulaOpen calculatorEconomicsFinancial Needs Pyramid CalculatorScore five layers of your financial foundation — survival, safety, support, growth, and freedom — with a stress test and what-if simulator.Best for: Seeing which money layer to strengthen first before chasing higher-level goals.FormulaXLSXChartsScenariosAdvancedOpen calculatorInvestingROI CalculatorSimple, date-based, and net ROI with annualised ROI (CAGR), a reverse target solver, and a two-investment comparison.Best for: Judging whether an investment paid off, its annual growth rate, and comparing two options.FormulaXLSXChartsScenariosOpen calculatorInvestingDividend Reinvestment CalculatorModel DRIP vs cash dividends, after-tax reinvestment, yield on cost, and a dividend income goal solver.Best for: Dividend income planning and the long-run effect of reinvesting.FormulaXLSXChartsScenariosOpen calculatorInvestingReal Estate Investment CalculatorTotal ROI on a rental property from cash flow, principal paydown, and appreciation, with annualized return and cash-on-cash.Best for: Evaluating a rental property purchase or comparing it against other investments.FormulaOpen calculatorTaxSales Tax CalculatorAdd US sales tax to a price or back it out of a receipt total, with combined state + average local rate presets for all 50 states.Best for: Working out US sales tax by state, forward or in reverse from a receipt.FormulaOpen calculatorTaxSalary & Take-Home Pay CalculatorEstimate take-home pay with sourced payroll models for the US, India, UK, Canada, and Australia, plus a net-to-gross solver.Best for: Seeing what actually lands in your account from salary, hourly, or CTC pay.FormulaXLSXScenariosAdvancedOpen calculatorTaxGlobal Import Duty CalculatorEstimate customs duty, tax, and total landed cost for any country, or India’s Basic Customs Duty, Social Welfare Surcharge, and IGST cascade.Best for: Turning a duty and tax rate you already know into a dollar amount and total landed cost.FormulaOpen calculatorBudget & CreditBudget CalculatorBuild a monthly and annual budget in simple or 65-line advanced mode, with savings rate, ratios, and a health score.Best for: Seeing your real monthly surplus or deficit and where the money goes.FormulaXLSXAdvancedOpen calculatorBudget & Credit50/30/20 Budget CalculatorSplit take-home pay into 50% needs, 30% wants, and 20% savings, compare your real spending, and test alternative ratios.Best for: Applying the 50/30/20 rule to your actual spending, not just your income.FormulaXLSXScenariosOpen calculatorBudget & CreditNet Worth CalculatorBuild a personal balance sheet — quick or 78-line detailed — with liquid and tangible net worth and debt analysis.Best for: Seeing what you own, what you owe, and how accessible your wealth really is.FormulaXLSXAdvancedOpen calculatorBudget & CreditDebt Payoff CalculatorSimulate up to 20 debts with snowball, avalanche, custom, or hybrid payoff order and find your debt-free date.Best for: Finding your debt-free date and the payoff order that fits you.FormulaXLSXScenariosOpen calculatorBudget & CreditDebt Payoff vs Investing CalculatorCompare ending net worth from paying extra toward a debt first against investing that money instead.Best for: Deciding whether extra cash should pay down debt or go into investing.FormulaScenariosOpen calculatorBusinessMarkup CalculatorPrice from cost across nine modes — markup, target margin, reverse cost ceilings, and ecommerce landed cost after fees.Best for: Setting a selling price from cost — without confusing markup and margin.FormulaXLSXScenariosAdvancedOpen calculatorBusinessBreak-Even CalculatorFind units and revenue break-even, contribution margin, target profit, and margin of safety, with sensitivity tables and a chart.Best for: Knowing how much you must sell to not lose money — and how much buffer you have.FormulaXLSXChartsScenariosAdvancedOpen calculatorBusinessEcommerce Profit CalculatorSee net profit per order after product costs, fees, shipping, ads, and returns, with break-even price and ROAS.Best for: Seeing what you actually keep per order — and which cost line is eating it.FormulaXLSXScenariosOpen calculatorBusinessLTV:CAC CalculatorCalculate CAC, discounted LTV, the LTV:CAC ratio, and CAC payback, with channel-by-channel decisions and scenarios.Best for: Judging whether acquisition spend pays back — and whether it is safe to scale.FormulaXLSXScenariosOpen calculatorBusinessPrice Elasticity of Demand CalculatorMeasure price elasticity of demand (midpoint and simple PED) and test how a price change affects revenue and profit.Best for: Deciding whether a price increase or discount will help revenue and profit.FormulaXLSXScenariosAdvancedOpen calculatorBusinessAI Agent Cost CalculatorModel per-attempt AI cost, retries, tool calls, caching, and human review to find the real cost per successful task.Best for: Knowing what an AI agent actually costs once retries, failures, and review are included.FormulaOpen calculatorBusinessDDP vs DAP Cost CalculatorCompare landed cost under DAP and DDP Incoterms — what the buyer pays upfront vs.Best for: Deciding whether to ship DAP or DDP, and knowing the real cost difference before quoting a buyer.FormulaOpen calculatorBusinessAltman Z-Score CalculatorAll three published models at once — different coefficients, different thresholds — with a warning when they disagree about the same company.Best for: Scoring a private or non-manufacturing company with the right model.FormulaScenariosAdvancedOpen calculatorMathOdds Ratio to Risk Ratio CalculatorConvert an odds ratio to a risk ratio at any baseline risk, with the interval converted too and the same odds ratio shown across eleven baselines.Best for: Turning a published odds ratio into a risk anyone can act onFormulaAdvancedOpen calculatorMathVIF CalculatorVariance inflation factors with Belsley-Kuh-Welsch condition indices and variance-decomposition proportions, so a near-dependency is named…Best for: Finding which predictors overlap, not merely that some of them doFormulaAdvancedOpen calculatorMathTwo-Proportion Z-Test CalculatorCompares two rates with the pooled z-test and a Newcombe interval for the difference, and shows that z² equals the 2×2 chi-square statistic…Best for: A/B tests and any comparison of “x of n” against “y of m”.FormulaAdvancedOpen calculatorMathKruskal-Wallis CalculatorApplies the tie correction and shows it against the uncorrected value, because on ordinal data it moves p from 0.054 to 0.027 — across…Best for: Three or more groups on ordinal or skewed data.FormulaAdvancedOpen calculatorMathBirthday Paradox CalculatorAnswers both questions the paradox conflates — 50.73% that some pair shares a birthday in a room of 23, and 5.86% that anyone shares yours…Best for: Coincidence odds, and hash collision thresholds.FormulaAdvancedOpen calculatorMathSimpson's Paradox CalculatorDetects when a pooled comparison contradicts every subgroup, then repairs it by standardising — which takes the real Berkeley admissions gap…Best for: Rate comparisons where the groups are mixed unevenly.FormulaAdvancedOpen calculatorMathProbability CalculatorTwo events, repeated trials and Bayes, with the three usual errors handled — the dropped overlap in P(A or B), n×p instead of the complement…Best for: Combining events without the classic mistakes.FormulaAdvancedOpen calculatorMathSkewness CalculatorAll three skewness conventions at once with the standard error beside them, because Excel SKEW runs 18.6% above the textbook formula at n=10…Best for: Asymmetry, judged against its own noise.FormulaAdvancedOpen calculatorMathNegative Binomial CalculatorShows both conventions at once — failures before the rth success and total trials differ by exactly r, so the same k gives two answers 32% apart…Best for: Waiting for the rth success, and overdispersed counts.FormulaAdvancedOpen calculatorMathWeibull Distribution CalculatorReliability probabilities with the hazard curve drawn beside the density — because the shape parameter is the hazard story: below 1 the risk…Best for: Deciding whether preventive replacement is worth anything.FormulaAdvancedOpen calculatorMathPoisson Distribution CalculatorPoisson probabilities with a dispersion test against your own variance — because a Poisson forces variance to equal the mean, and real count…Best for: Checking a Poisson fits before trusting its tail.FormulaAdvancedOpen calculatorMathNormal Distribution CalculatorProbabilities under a normal curve in all four directions with the region shaded — and the empirical rule given exactly, because two standard…Best for: Tail probabilities a printed z-table stops short of.FormulaAdvancedOpen calculatorMatht-test CalculatorOne-sample, two-sample and paired t-tests defaulting to Welch, with Student's pooled version printed beside it — and a warning when the two…Best for: Not inheriting an equal-variance assumption you never checked.FormulaAdvancedOpen calculatorMathStandard Error CalculatorStandard error of a mean or proportion, printed beside the standard deviation it gets confused with — the ratio is always √n, and at n = 50 that…Best for: Telling a spread apart from a precision before you draw the error bars.FormulaAdvancedOpen calculatorMathMargin of Error CalculatorMargin of error for a percentage or an average, shown across seven sample sizes so the square-root law is visible — every doubling buys exactly…Best for: Seeing what precision actually costs before you buy it.FormulaAdvancedOpen calculatorMathp-value CalculatorA p-value from a t or z statistic, one- or two-tailed — with a panel that holds an effect fixed and grows the sample, so you can watch…Best for: Seeing why a small p-value does not mean a large effect.FormulaAdvancedOpen calculatorMathGrade CalculatorCalculate your weighted overall grade from categories or points, or find the score you need on your final exam.Best for: Checking a current course grade or the score needed on a final.FormulaScenariosOpen calculatorMathGPA CalculatorCalculate your GPA from letter grades or percentages and credit hours, or combine a new term with your existing cumulative GPA.Best for: Averaging grades across multiple courses on the standard 4.0 scale.FormulaScenariosOpen calculatorMathPercentage CalculatorSolve X% of Y, what percent X is of Y, reverse percentage, increase/decrease, discounts, and tax, tip, or commission.Best for: Every everyday percentage question in one tool.FormulaXLSXScenariosOpen calculatorMathPercentage Change CalculatorWork out percentage increase or decrease, reverse change, loss recovery, percentage points, multi-period change, and CAGR.Best for: Analysing how much a value rose or fell — and what it takes to reverse it.FormulaXLSXScenariosOpen calculatorMathDiscriminant CalculatorEvaluate b² − 4ac, the cubic and quartic discriminants, or D = f_xx·f_yy − (f_xy)² for the second-derivative test, in exact arithmetic so…Best for: Knowing what the roots are like before you find them.FormulaAdvancedOpen calculatorMathFOIL CalculatorMultiply two binomials with all four products named — First, Outer, Inner, Last — shown as a grid too, with difference of squares and perfect…Best for: Seeing the four products, not just the answer.FormulaAdvancedOpen calculatorMathMultiplying Polynomials CalculatorMultiply polynomials of any size in any number of variables, by grid, vertical or term-by-term layout, with the product count that catches…Best for: Anything bigger than two brackets of two terms.FormulaAdvancedOpen calculatorMathRational Zeros CalculatorList every rational root candidate from the rational root theorem, test each one, divide out the hits by synthetic division, and use the bound…Best for: Seeing the search, not just the roots it finds.FormulaAdvancedOpen calculatorMathDescartes' Rule of Signs CalculatorCount the sign variations in f(x) and f(-x), list every combination of positive, negative and complex roots the rule permits, and see which one…Best for: Reading a rule that gives possibilities, not a count.FormulaAdvancedOpen calculatorMathPerfect Square Trinomial CalculatorTest whether a trinomial is a perfect square against all three conditions, name which one failed, and give the constant that would fix it…Best for: Finding out why a trinomial is not a perfect square.FormulaAdvancedOpen calculatorMathSquare of a Binomial CalculatorExpand (a plus or minus b) squared with the middle term named and a numeric example of exactly what the (a+b)^2 = a^2+b^2 mistake costs…Best for: Never dropping the middle term again.FormulaAdvancedOpen calculatorMathInverse Variation CalculatorFind k from one pair and predict any other for y = k/x or y = k/x^n, with the asymptotes treated as content, plus joint and combined variation…Best for: The constant product, and why x = 0 is not in the domain.FormulaAdvancedOpen calculatorMathInterval Notation CalculatorConvert between inequality, interval notation, set-builder form and a number-line graph in every direction, including absolute values, unions…Best for: Getting the brackets and the or-versus-and right.FormulaAdvancedOpen calculatorMathGraphing Quadratic Inequalities CalculatorSolve a quadratic inequality by sign chart rather than by four memorised cases, and shade the region for the two-variable form…Best for: One method that keeps working past quadratics.FormulaAdvancedOpen calculatorMathSubset CalculatorTest whether one set is a subset, a proper subset, equal or disjoint — and when the answer is no, name the exact element that breaks it.Best for: An answer with a witness, not just a verdict.FormulaAdvancedOpen calculatorMathUnion and Intersection CalculatorSix set operations on two or three sets at once, with the Venn regions, inclusion-exclusion checked against the real counts, and De Morgan…Best for: Identities computed rather than quoted.FormulaAdvancedOpen calculatorMathComplex Conjugate CalculatorThe conjugate, and everything it does: the sum, difference, product and quotient identities computed on your number, the reflection geometry…Best for: Why the conjugate matters, not just how to write it.FormulaAdvancedOpen calculatorMathComplex Root CalculatorAll n roots of any complex number by De Moivre, exact wherever a root is a Gaussian rational, arranged as the regular n-gon they form…Best for: All n of them, not just the principal one.FormulaAdvancedOpen calculatorMathError Function Calculatorerf, erfc and the inverse to full double precision through the incomplete gamma function, with the normal-distribution conversion…Best for: Tail probabilities that survive past x = 3.FormulaAdvancedOpen calculatorMathGamma Function CalculatorGamma, log-gamma, digamma and beta with the factorial shift stated every time, values reconstructed past the double overflow, and the poles…Best for: Factorials of non-integers, and past 170.FormulaAdvancedOpen calculatorMathBessel Function CalculatorJ, Y, I and K plus the spherical pair, with the zeros that set drum modes and waveguide cutoffs, the recurrence and Wronskian checked…Best for: The zeros, which are what the physics needs.FormulaAdvancedOpen calculatorMathQuaternion CalculatorExact quaternion arithmetic showing both pq and qp every time, both quotients rather than one, and the rotation a unit quaternion represents…Best for: Non-commutativity treated as the subject, not a footnote.FormulaAdvancedOpen calculatorMathMultiplying Binomials CalculatorMultiply two to six binomials with the 2^n product count as the check, the build-up shown one bracket at a time, and the roots reading that…Best for: Past two brackets, where FOIL runs out of letters.FormulaAdvancedOpen calculatorMathInequality to Interval Notation CalculatorSolve a linear, chained or absolute-value inequality and write the answer in interval notation, with the sign flip marked at the step where it…Best for: Solving first — the notation page does not.FormulaAdvancedOpen calculatorMathGraphing Inequalities on a Number LinePlot up to six inequalities on one shared number line, read the overlap and the union straight off it, and see which conditions conflict…Best for: Comparing several conditions at once.FormulaAdvancedOpen calculatorMathTip CalculatorCalculate the tip amount, total bill, and per-person share for restaurants, bars, delivery, and other services.Best for: Splitting a bill and tip evenly among any number of people.FormulaOpen calculatorMathFraction CalculatorAdd, subtract, multiply and divide fractions and mixed numbers exactly, with the least common denominator chosen, the cross-cancelling done…Best for: When the working is what gets marked, not the answer.FormulaAdvancedOpen calculatorMathFraction to Decimal CalculatorConvert a fraction to its exact decimal, with the length of the repeat worked out from the denominator before dividing and the long division…Best for: Knowing how long the repeat is before you divide.FormulaAdvancedOpen calculatorMathGCF CalculatorThe greatest common factor of two to six numbers with all three routes shown — the shared primes to their lower powers, Euclid line by line…Best for: When you want to see where the divisor came from.FormulaAdvancedOpen calculatorMathPrime Factorization CalculatorBreak any number into primes with the division ladder shown, the number of trial divisions reported, and the argument for why the search can…Best for: Seeing why trial division to the root is enough.FormulaAdvancedOpen calculatorMathDivisibility Test CalculatorEvery divisibility rule from 2 to 16 applied to your number, each with its working, the reason it holds, and the true remainder beside it as a check.Best for: Rules you can verify rather than believe.FormulaAdvancedOpen calculatorMathFactorial CalculatorFactorials with every digit exact — 100 factorial is 158 of them — plus the trailing-zero count derived from Legendre's formula and Stirling's error.Best for: Exactness past where a calculator gives up.FormulaAdvancedOpen calculatorMathWeighted Average CalculatorEach value carries the weight you give it, with every item's share of the total shown as a percentage so you can see what is actually driving…Best for: Course grades, portfolio returns, anything where the items are not equally important.FormulaAdvancedOpen calculatorMathRounding CalculatorAll seven rounding rules on the same number at once, so the disagreement at a tie is visible rather than buried inside whichever one your…Best for: Deciding how a half should be treated, and matching a spreadsheet that disagrees.FormulaAdvancedOpen calculatorMathModulo CalculatorAll three conventions at once, because −7 mod 3 is −1 in JavaScript and 2 in Python and a page that gives only one of those is wrong for half…Best for: Matching a language's answer, and understanding why they differ.FormulaAdvancedOpen calculatorMathModular Exponentiation Calculator7^128 mod 13 without ever building the 109-digit power.Best for: Working through an RSA or Diffie-Hellman example by hand.FormulaAdvancedOpen calculatorMathModular Inverse CalculatorThe number that undoes a multiplication modulo n, from the extended Euclidean algorithm — or the shared factor that proves no such number exists.Best for: Cipher keys, RSA exponents, and dividing where division does not exist.FormulaAdvancedOpen calculatorMathChinese Remainder Theorem CalculatorSolves a system of congruences including the moduli that are not coprime, which most tools refuse — with the merge shown one congruence at a time.Best for: Counting puzzles with several leftover conditions, and CRT exercises.FormulaAdvancedOpen calculatorMathPascal’s Triangle CalculatorThe triangle drawn to any row up to 40, exact on big integers, with the row sum as a power of two and each diagonal's meaning named.Best for: Binomial expansions and choosing-k-from-n by inspection.FormulaAdvancedOpen calculatorMathCollatz Conjecture CalculatorHalve it or triple it until 1 — with the climb drawn on a log scale, the peak, the stopping time, and a plain statement that the conjecture is…Best for: Exploring one of the simplest unsolved problems in mathematics.FormulaAdvancedOpen calculatorMathCoterminal Angle CalculatorThe principal angle between 0° and 360°, the nearest negative one, and the family θ + 360n they all belong to — reduced by exact division, not…Best for: Normalising an angle before anything else is done with it.FormulaAdvancedOpen calculatorMathComplementary and Supplementary Angles CalculatorBoth at once, plus the explement — and an honest answer when there is none, since an obtuse angle has no complement and a negative number is not one.Best for: School geometry, and checking which of the two a problem means.FormulaAdvancedOpen calculatorMathPercent to Goal CalculatorProgress against a target, plus the pace the remaining periods actually need — the number a progress bar never shows and nobody works out…Best for: Quotas, campaigns and any target with a deadline.FormulaAdvancedOpen calculatorMathUnit Circle CalculatorWhere an angle lands, with exact surd coordinates and the radian measure as a multiple of π — because the coordinates ARE the cosine and sine.Best for: Seeing where the trig values come from rather than memorising them.FormulaAdvancedOpen calculatorMathMidpoint CalculatorThe midpoint of a segment, plus the reverse problem nobody else solves: given one endpoint and the midpoint, where is the other endpoint?Best for: The endpoint problem, which is the one that gets set in exams.FormulaAdvancedOpen calculatorMathAbsolute Value CalculatorAbsolute value as a distance from zero — plus the distance between two numbers, and a relative change from zero reported as undefined rather…Best for: Absolute change versus relative change, and when the second has no value.FormulaAdvancedOpen calculatorMathFloor and Ceiling CalculatorFloor, ceiling and truncation side by side — because for negative numbers those are three different answers, and floor(−2.5) is −3 while…Best for: The negative-number case that agrees on every positive and disagrees on every negative.FormulaAdvancedOpen calculatorMathPlace Value CalculatorEvery digit named and valued, in all three expanded forms and in words — including the decimals, where the first place after the point is tenths…Best for: Whichever expanded form the worksheet actually asked for.FormulaAdvancedOpen calculatorMathConsecutive Integers CalculatorThe run that sums to your target, or the reason there is not one — plus every run a number admits, and why the powers of two admit none.Best for: The 'no solution' case, where the reason is worth more than the answer.FormulaAdvancedOpen calculatorMathAbsolute Value Equation CalculatorBoth cases written out, in interval and set-builder notation — with the distinction the topic turns on: a less-than is an AND, a greater-than is…Best for: Not writing a greater-than as a chain, which describes the empty set.FormulaAdvancedOpen calculatorMathPolar Coordinates CalculatorCartesian to polar and back, in two dimensions or three — with the angle from atan2, so a point in a left-hand quadrant is not reported 180°…Best for: The quadrant, which atan(y/x) throws away.FormulaAdvancedOpen calculatorMathPolygon Area CalculatorThe shoelace formula on any number of corners, kept exact — with the signed area whose sign is the winding direction, and a clear warning where…Best for: Areas from surveyed coordinates, without triangulating first.FormulaAdvancedOpen calculatorMathMatrix Decomposition CalculatorLU, QR and Cholesky — with LU exact and the other two decimal, because square roots are irrational, and the page labels which is which rather…Best for: Cholesky failing, which is the positive-definiteness test itself.FormulaAdvancedOpen calculatorMathRegular Polygon CalculatorArea, perimeter, apothem, circumradius and angles from whichever measurement you have — plus whether the polygon can be drawn with compass…Best for: The apothem, which the area formula wants and nobody measures.FormulaAdvancedOpen calculatorMathPrism CalculatorVolume and both surface areas for rectangular, triangular and trapezoidal prisms — with the triangular base solved from three measured side…Best for: Measuring a real object, where the height is the one thing you cannot reach.FormulaAdvancedOpen calculatorMathLogarithm Rules CalculatorExpand or condense a logarithm step by step, with the rule that produced each term — and an explicit statement that log(a + b) is not log a + log b.Best for: The fourth rule people apply, which does not exist.FormulaAdvancedOpen calculatorEconomicsDiminishing Returns CalculatorTurn input-output data into total, marginal, and average product and find the point of diminishing returns.Best for: Finding where adding more input stops paying off.FormulaXLSXChartsScenariosAdvancedOpen calculatorEconomicsOpportunity Cost CalculatorCompare two choices to see net value, opportunity cost, explicit vs implicit costs, and risk-adjusted scenarios.Best for: Comparing two choices and the value you give up.FormulaXLSXScenariosOpen calculatorEconomicsMarginal Utility CalculatorTurn a utility table into total and marginal utility and utility per dollar, and find the satiation point.Best for: Seeing where each extra unit stops being worth it.FormulaXLSXChartsScenariosOpen calculatorEconomicsMarket Equilibrium CalculatorSolve equilibrium price and quantity from linear demand and supply, with surplus, a shift simulator, and tax incidence.Best for: Solving equilibrium price, quantity, surplus, and policy interventions.FormulaXLSXChartsScenariosAdvancedOpen calculatorEconomicsConsumer Surplus CalculatorFind the value buyers gain above what they pay, from the choke price, market price, and quantity sold.Best for: Sizing the welfare gain that flows to buyers under a linear demand curve.FormulaChartsOpen calculatorEconomicsProducer Surplus CalculatorFind the value sellers gain above their minimum acceptable price, from the market price and quantity sold.Best for: Sizing the welfare gain that flows to sellers under a linear supply curve.FormulaChartsOpen calculatorEconomicsDeadweight Loss CalculatorSize the welfare triangle a per-unit tax destroys, alongside the tax revenue it actually raises.Best for: Measuring the efficiency cost of a tax, price control, or other price wedge.FormulaChartsOpen calculatorEconomicsComparative Advantage CalculatorFind comparative and absolute advantage between two producers and two goods, plus the mutually beneficial trade range.Best for: Working out who should specialize in what, and why trade still pays off.FormulaScenariosOpen calculatorHealthBMI CalculatorCalculate BMI in metric or imperial units, see your adult category and healthy-weight range, with clear limitations and a separate under-18 result.Best for: A quick, honest BMI screening check with real limitations explained.FormulaOpen calculatorHealthTDEE CalculatorEstimate BMR, TDEE and daily calorie needs with the Mifflin-St Jeor equation, a maintenance range, and calorie scenarios for losing…Best for: Finding a realistic starting-point calorie target before setting a goal.FormulaOpen calculatorHealthCalorie Deficit CalculatorCalculate a daily calorie deficit and an adaptive weight-loss timeline range from your TDEE, with a safety-floor warning and a scenario comparison.Best for: Planning a realistic weight-loss timeline with an honest planning range, not one fixed date.FormulaOpen calculatorTime & DateTime Zone ConverterConvert a date and time between EST, IST, GMT, UTC, CET, PST, or any IANA time zone, with live daylight-saving handling and a multi-zone world…Best for: Scheduling across time zones without manually tracking daylight saving.FormulaOpen calculatorTime & DateTimesheet CalculatorCalculate hours worked across a week, two weeks, or a month from clock-in and clock-out times, with lunch-break deduction, overtime…Best for: Turning daily clock-in/out times into decimal-hour payroll totals.FormulaOpen calculatorTime & DateAge CalculatorCalculate exact age in years, months, and days from a birth date, with total days lived, day born, a next-birthday countdown, and Excel/SQL/code…Best for: Exact age as of any date, not just today, with the calendar-correct method.FormulaOpen calculatorTime & DateTime Percentage CalculatorWork out what percentage one span of time is of another, or the percentage increase or decrease between an old and a new duration.Best for: Minutes-of-an-hour, work-hour, or race/lap time percentages, and time savings.FormulaOpen calculatorTime & DateDays CalculatorCount days between two dates, add or subtract days, or count business days excluding weekends and holidays, with a full calendar breakdown.Best for: Days between dates, a target date N days out, or a business-day deadline.FormulaOpen calculatorHome & EnergySolar Panel Roof-Fit CalculatorEstimate how many solar panels fit your roof, the system size in kW, yearly generation, and cost, incentive, and payback for India, the USA…Best for: Sizing a rooftop system from your roof area before getting an installer quote.FormulaOpen calculatorHome & EnergyGutter CalculatorSize gutters and downspouts from roof area and rainfall intensity (SMACNA, AS/NZS 3500.3, or BS EN 12056-3), or estimate materials and cost from…Best for: Choosing a gutter and downspout size, or pricing a gutter replacement.FormulaOpen calculatorHome & EnergyInsulation CalculatorCalculate insulation depth and quantity — loose-fill bags, batt/roll/board packages, or spray-foam board-feet — plus R-value achieved…Best for: Sizing attic, wall, ceiling, or floor insulation by R-value, in whatever format you’re buying it.FormulaOpen calculatorHome & EnergyRoofing CalculatorCalculate roof area, pitch, and roofing squares from a footprint, or estimate shingle bundles, metal sheets and weight, or flat-membrane…Best for: Working out roofing squares and a materials/cost estimate before getting a roofer's quote.FormulaOpen calculatorHome & EnergyDecking CalculatorCalculate decking boards, joists, and screws or hidden clips needed for any deck — in feet/inches or metres/millimetres — plus an optional…Best for: Sizing a deck’s boards, frame, and fasteners by area, in whatever units and fastener style you’re using.FormulaOpen calculatorHome & EnergyFence CalculatorCalculate fence posts, rails, and pickets from length, height, and spacing, or estimate wood, vinyl, or chain-link materials, cost, and stain needed.Best for: Working out posts, pickets, and concrete before buying materials, or pricing a fence by region.FormulaOpen calculatorEverydayBicycle Tire Pressure CalculatorEstimate front and rear bicycle tire pressure from your weight, tire width, tire type, and terrain, using a published formula.Best for: Finding a starting-point tire pressure instead of guessing.FormulaScenariosOpen calculatorDIY & MaterialsConcrete CalculatorCalculate cubic yards of concrete needed for a slab, footing, or column, and how many 40, 60, or 80 lb pre-mix bags to buy.Best for: Ordering the right amount of concrete before a pour, in yards or bags.FormulaScenariosOpen calculatorDIY & MaterialsPaint CalculatorCalculate how many gallons of paint you need for a room from its dimensions, doors, windows, and number of coats.Best for: Buying the right number of gallons before a repaint, walls and ceiling included.FormulaScenariosOpen calculatorDIY & MaterialsGravel CalculatorCalculate cubic yards or cubic metres of gravel, crushed stone, or road base, and tons or tonnes, for driveways, paths, and drains.Best for: Ordering the right amount of gravel or crushed stone before delivery, in US or metric units.FormulaScenariosRegion modesOpen calculatorConversionMillion, Billion and Trillion ConverterThousand to trillion in both naming conventions, since a billion is 10⁹ in the US and 10¹² across much of Europe.Best for: Reading a large figure when the source did not say which convention its “billion” follows.FormulaScenariosOpen calculatorConversionArea ConverterSquare feet, square metres, acres and hectares, with the factors squared for you — a square metre is 10.76 sq ft, not 3.28.Best for: Floor and land area, where reaching for the length factor is a threefold error.FormulaScenariosOpen calculatorConversionEnergy ConverterJoules, kilojoules, calories, food Calories, kWh, BTU and therms — with the two calories listed apart, since one is a thousand of the other.Best for: Nutrition labels and utility bills, where “calorie” means two different things.FormulaScenariosOpen calculatorConversionRoman Numerals ConverterNumbers to Roman numerals and back, 1 to 3,999 — reading the older spellings like IIII and writing the standard modern form.Best for: Years on cornerstones and credits, regnal numbers, and clock faces.FormulaScenariosOpen calculatorHome & EnergykWp to kWh ConverterA solar array’s rating into a year’s energy, by region — because the same panels make more than twice as much in Arizona as in Scotland.Best for: A quote in kWp and a question in kWh, which no single factor connects.FormulaScenariosOpen calculatorConversionTPI to mm Pitch ConverterThreads per inch to millimetre pitch, with the flank angle and taper that decide whether two threads mate — and a “half-inch” pipe thread that…Best for: An unmarked bolt or fitting, where nearest is never compatible.FormulaScenariosOpen calculatorConversionFlight Level to Feet ConverterFlight levels into real heights using the day’s altimeter setting — because FL100 is only 10,000 ft when the pressure happens to be standard.Best for: Understanding altimetry, where a level is a pressure rather than a height.FormulaScenariosOpen calculatorEverydayBaker’s Percentage CalculatorA bread formula between percentages and grams, with the levain split out — because the percentages are of the flour and total nearly 200.Best for: Scaling a recipe, or reconciling two doughs both described as 75% hydration.FormulaScenariosOpen calculatorConversionGauss to Tesla ConverterTesla, gauss, oersted, weber and magnet grades grouped by quantity — because gauss and oersted measure different things and only look identical…Best for: A magnet or coil datasheet mixing SI and CGS units.FormulaScenariosOpen calculatorHealthIU to mg ConverterInternational Units to micrograms for vitamin A, D, E and insulin — with the substances that have no conversion listed rather than quietly left out.Best for: A supplement label in IU next to one in micrograms, for the same vitamin.FormulaScenariosOpen calculatorConversionNPK Fertilizer ConverterA fertiliser grade turned into actual N, P and K — because the second and third numbers are oxides, so 10-10-10 is really 10-4.4-8.3.Best for: Matching a bag against a soil test, which reports elements rather than oxides.FormulaScenariosOpen calculatorTime & DateTime Unit ConverterNanoseconds to fortnights exactly, with months as a real calendar range and four different years side by side — because two of those units have…Best for: Anything that multiplies a month or a year, where the convention was never stated.FormulaScenariosOpen calculatorHome & EnergyCord of Wood CalculatorCords, face cords and steres with the heat each species holds — and why a face cord is a quarter or a half of a cord depending only on the log length.Best for: Buying firewood, where “a cord” is the only measure with a definition.FormulaScenariosOpen calculatorConversionBushel to kg ConverterBushels to kg, tonnes and quintals for eleven crops, with yield per acre and hectare — because a bushel is a volume sold at a different weight…Best for: A yield or a load quoted in the other country’s convention.FormulaScenariosOpen calculatorConversionEC to TDS ConverterµS/cm, mS/cm, dS/m and ppm on all three scales at once — because the ppm factor is a meter convention, not a property of the water.Best for: Two meters disagreeing on the same tank, or a recipe written on the other scale.FormulaScenariosOpen calculatorConversionGold Purity ConverterKarat, fineness, tola and troy ounce — what 916 means, how much gold is really in a piece, and why a carat is not a karat.Best for: A hallmark you cannot read, or a rate quoted in a unit you do not use.FormulaScenariosOpen calculatorConversionOctane Rating ConverterRON, MON and AKI across US, UK, EU, India and Japan pumps — with the real uncertainty band, since no pump prints the sensitivity the conversion needs.Best for: Driving in another country, where the pump number is on a different scale.FormulaScenariosOpen calculatorConversionViscosity ConvertercP, cSt, poise, stokes and Saybolt seconds — asking for the density the bridge needs, and showing that 4.63 is a curve rather than a factor.Best for: An oil data sheet in one family of units and a spec written in the other.FormulaScenariosOpen calculatorConversionForce ConverterNewtons, kgf, lbf, kip, poundals and dynes with exact factors — keeping mass in its own panel, and the three tons-force apart.Best for: A load chart marked “kg”, or a “ton” that could be three different forces.FormulaScenariosOpen calculatorEverydayCake Pan Size ConverterScale a recipe to the tin you actually have — by area rather than diameter, showing the answer most people get beside the right one.Best for: A recipe written for a tin you do not own, where the obvious arithmetic is twice wrong.FormulaScenariosOpen calculatorEverydayClothing Size ConverterUS, UK and EU sizes from body measurements — with men’s sizes as the measurements they are, and women’s marked as the conventions they are.Best for: Ordering across markets, where a number means a measurement on one rail and nothing on the other.FormulaScenariosOpen calculatorBusinessDimensional Weight CalculatorVolumetric weight under every common divisor, the billable figure, and the density threshold that decides which rule applies.Best for: A light bulky parcel, where the scale reading is not what you pay for.FormulaScenariosOpen calculatorConversionTextile Weight ConverterYarn counts between tex, denier, Nm and Ne, and fabric weight between GSM and ounces — keeping them apart, because no factor connects them.Best for: A spec sheet mixing counts and weights, where half the systems run backwards.FormulaScenariosOpen calculatorEverydayBra Size ConverterUS, UK and EU sizes from two measurements, with both band methods and the sister sizes — and why a UK G is not a US G.Best for: Ordering across markets, where the letters stop agreeing above DD.FormulaScenariosOpen calculatorEverydayRing Size ConverterUS, UK, EU and Japanese ring sizes from the circumference in millimetres — and why no two published charts agree.Best for: Ordering a ring from another country, or from a chart you do not trust.FormulaScenariosOpen calculatorConversionPixel Density CalculatorPPI, dot pitch and physical size from any resolution — plus pixels per degree, which is what decides whether you can see the pixels.Best for: Choosing a monitor, where PPI alone ranks screens backwards.FormulaScenariosOpen calculatorConversionTyre Size CalculatorSidewall, diameter and rolling circumference from any tyre code — plus exactly how far a size change throws off the speedometer.Best for: Considering a different tyre size, where the speedometer error is the part nobody mentions.FormulaScenariosOpen calculatorConversionAspect Ratio CalculatorExact ratio from any resolution, the missing dimension, and what letterboxing costs — flagging the resolutions that are not the ratio they claim.Best for: Checking whether a screen or a video really is the ratio it is sold as.FormulaScenariosOpen calculatorConversionWire Gauge ConverterAWG and SWG to mm, mm² and circular mils, with resistance and voltage drop — and the 14–21% gap the equivalence charts hide.Best for: A design specified in one system and built in the other.FormulaScenariosOpen calculatorEverydayShoe Size ConverterUS, UK, EU and centimetres from your actual foot length — with both US women’s scales, which disagree by half a size.Best for: Ordering from another country, where the size on the box is not the size you wear.FormulaScenariosOpen calculatorInvestingNPV CalculatorNet present value across uneven cash flows, with payback period and profitability index alongside.Best for: Deciding whether a project clears its cost of capital.FormulaOpen calculatorEconomicsLabor Force Participation Rate CalculatorThe share of the working-age population in the labour force — the denominator the unemployment rate depends on.Best for: Seeing whether a falling unemployment rate reflects jobs or people leaving.FormulaOpen calculatorInvestingBitcoin Return CalculatorWhat an amount invested at one price is worth at another, with the entry fee taken off before the coins are bought.Best for: Starting from the money you put in rather than the quantity you hold.FormulaOpen calculatorInvestingWeighted Average Expense Ratio CalculatorA portfolio fee weighted by what sits in each fund, with the annual cost in money rather than percent.Best for: Finding what a multi-fund portfolio actually costs to hold each year.FormulaOpen calculator

New here? These six cover the most common decisions across finance, budgeting, business, math, and tax.

FinanceMortgage CalculatorSize up a home purchase — payment, interest, taxes, and insurance.Open calculatorBudget & CreditBudget CalculatorSee your monthly surplus, savings rate, and where the money goes.Open calculatorBusinessProfit Margin CalculatorFind gross, operating, and net margin, and the price for a target.Open calculatorMathPercentage CalculatorPercentages, increases, decreases, and “what percent of” in one place.Open calculatorFinanceCompound Interest CalculatorProject how savings or investments grow with compounding over time.Open calculatorTaxIncome Tax CalculatorEstimate tax across progressive bands and compare two scenarios.Open calculator

Start with what you want to do

Pick a goal and jump straight to the right set of tools.

Buy or refinance a home

Plan savings or investing

Understand tax and take-home pay

Fix budget and debt

Run a business or store

Solve math & statistics

Learn economics & decisions

Browse by category

Every published category in one place. Open a category for its full set of calculators.

Finance

20 tools

Mortgages, loans, amortization, interest, savings, and retirement planning.

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Investing

9 tools

Growth, returns, income, compounding, regular investing, and withdrawal planning.

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Budget & Credit

6 tools

Budgets, debt payoff, credit card payoff, net worth, and personal cash flow.

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Business

11 tools

Margins, markup, break-even, ecommerce profit, ROAS, LTV:CAC, and pricing decisions.

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Tax

5 tools

Income tax, VAT/GST, salary, take-home pay, and practical tax estimates.

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Economics

10 tools

Opportunity cost, marginal utility, diminishing returns, pricing response, and production models.

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Math

73 tools

Percentages, percentage change, standard deviation, variance, dataset analysis, and a scientific calculator.

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Health

4 tools

BMI, daily calorie needs (TDEE), and a calorie-deficit weight-loss timeline.

View Health

Time & Date

6 tools

Time zone conversion, work-hour timesheets, exact-age calculations, date differences and durations, and time-based percentages.

View Time & Date

Home & Energy

8 tools

Rooftop solar sizing, gutters, insulation, roofing materials, and deck planning, with cost estimates.

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Everyday

7 tools

Practical everyday calculators, starting with bicycle tire pressure.

View Everyday

DIY & Materials

3 tools

Material quantities for DIY projects, starting with concrete for slabs, footings, and columns.

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Conversion

19 tools

Move a quantity between units or number systems and see the factor that did it — starting with lakh and crore against million and billion, commas and all.

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What the badges mean

Formula — Shows the calculation method and a worked example.

XLSX — Downloadable Excel/CSV workbook generated from your inputs.

Charts — Visual breakdown of the result.

Scenarios — Compare different assumptions side by side.

Amortization — Full payment-by-payment schedule.

Region modes — Country-specific labels or assumptions where available.

Advanced — Deeper planner with multiple modes.

Recently improved

What we have upgraded lately — the site is actively maintained.

Not sure which calculator to use?

Quick guidance when two tools look similar.

Mortgage Calculator vs Loan Calculator

Use Mortgage for a home purchase with taxes, insurance, and PMI; use Loan for any general fixed loan.

Budget Calculator vs 50/30/20 Budget Calculator

Budget is a full line-by-line plan; 50/30/20 is a quick needs/wants/savings split.

Profit Margin Calculator vs Markup Calculator

Margin is profit as a share of price; markup is profit as a share of cost.

ROI Calculator vs Investment Calculator

ROI measures a single investment’s return; Investment projects growth from contributions over time.

VAT/GST Calculator vs Income Tax Calculator

VAT/GST works on a price; Income Tax works on earnings and brackets.

Debt Payoff Calculator vs Credit Card Payoff Calculator

Debt Payoff compares snowball vs avalanche across debts; Credit Card focuses on one card and minimum-payment traps.

Frequently asked questions

Choosing a calculator and reading the results.

What calculators are available on Calculator Matters?

Formula-backed calculators across 13 categories — Finance, Investing, Budget & Credit, Business, Tax, Economics, Math, Health, Time & Date, Home & Energy, Everyday, DIY & Materials and Conversion — covering 181 tools in total.

How is my data handled when I use a calculator?

Every calculator runs directly in your browser for educational planning, and the figures you enter for a basic calculation are not sent to a server.

Do the calculators show formulas?

Yes. Every calculator shows the formula it uses, the assumptions behind it, and a worked example, so you can reproduce the result yourself.

Which calculators include downloadable Excel workbooks?

Most do — including the mortgage, loan, budget, debt-payoff, profit-margin, and tax tools. Look for the “XLSX” badge on a calculator card, or filter by it above. The workbook is generated from the values you enter.

Why may results differ from banks, tax authorities, or brokers?

They use your exact rate, fees, rounding, eligibility, and current rules — which a general calculator cannot know. Treat results as planning estimates and confirm with official figures.

Are these results financial, tax, legal, business, or medical advice?

No. They are educational estimation tools, not professional advice of any kind, and they do not determine loan approval.

How should I choose the right calculator?

Start from a goal in “Start with what you want to do”, use the search box, or filter by category and feature. Each card shows what the tool does and whether it offers charts, scenarios, or a workbook.

Can I use these calculators outside the United States?

Yes. The tools are currency-neutral — you enter your own rates and amounts and read results in your own currency. Tax and legal rules vary by country, so confirm local rules with a local source.

Can I put these calculators on my own website?

Yes. Most tools on this site can be embedded with a single script tag, and results always match the full calculator page. See website calculator widgets for the snippet and options.

Is there a calculator app I can download, or does this work on my phone?

These are free web calculators — no download or app needed. They work the same in any mobile or desktop browser; open the page and use it directly, with no account or installation required.

Do you have an age calculator or date calculator (days between dates)?

Yes. Calculator Matters includes an Age Calculator for calculating exact age from a date of birth, and a Days Calculator for finding the number of days between two dates. There is no separate tool named “Date Calculator” — that date-difference use case is covered by the Days Calculator. You can open both directly from the Calculator Library.

All results are educational and planning estimates only — not financial, tax, legal, business, or medical advice. Verify important decisions with qualified professionals and official sources. See our Methodology, Editorial Policy, Corrections, and Disclaimer.