Calculator library

Calculators

Find formula-backed calculators for money, tax, investing, business, math, and everyday planning.

Calculator Matters provides free educational calculators for loans, tax, investing, budgets, business, ecommerce, math, statistics, and economics. Many include formulas, explanations, scenario comparisons, charts, and downloadable Excel workbooks.

40 calculators

FinanceMortgage CalculatorEstimate monthly payments, interest, taxes, insurance, PMI, and amortization using practical home-loan assumptions.FormulaXLSXChartsScenariosAmortizationAdvancedRegion modesOpen calculator FinanceCompound Interest CalculatorSee how savings grow as interest earns interest, with adjustable contributions and compounding frequency.FormulaChartsOpen calculator InvestingInvestment CalculatorThe master investment growth calculator — lump sum, regular contributions, goal planning, and future- vs present-va…FormulaXLSXChartsScenariosAdvancedOpen calculator InvestingRegular Investment CalculatorProject how regular monthly contributions grow over time — SIP-style investing, dollar-cost averaging, inflation-ad…FormulaChartsOpen calculator InvestingRetirement Withdrawal CalculatorEstimate how long your savings may last with regular withdrawals — portfolio drawdown, safe withdrawal rate, inflat…FormulaXLSXChartsOpen calculator Math & StatisticsStandard Deviation CalculatorA full descriptive-statistics analyzer — sample & population SD, variance, mean, median, quartiles, IQR, MAD, CV, s…FormulaXLSXChartsScenariosOpen calculator Business & EcommerceProfit Margin CalculatorA full profitability cockpit — gross, contribution, operating, and net margin across simple, advanced, ecommerce, s…FormulaXLSXScenariosAdvancedOpen calculator TaxIncome Tax CalculatorEstimate income tax six ways — quick estimate, unlimited custom progressive bands, a sourced US federal mode (2025/…FormulaXLSXScenariosAdvancedRegion modesOpen calculator FinanceLoan CalculatorWork out the monthly payment, total interest, and payoff date for any fixed-rate loan from the amount, rate, and term.FormulaXLSXAmortizationOpen calculator Budget & CreditCredit Card Payoff CalculatorPlan up to 20 cards with issuer-style minimums that recalculate monthly, promo APRs, annual fees, and credit utiliz…FormulaXLSXScenariosOpen calculator Business & EcommerceBreak-Even ROAS CalculatorA CFO-grade ad-profitability tool — marginal and business-level break-even ROAS, target ROAS for a desired net marg…FormulaXLSXScenariosOpen calculator TaxVAT/GST CalculatorAdd or remove VAT, GST, HST, or consumption tax from a price, solve tax-inclusive and tax-exclusive values, calcula…FormulaXLSXRegion modesOpen calculator FinanceMortgage Refinance CalculatorCompare your current mortgage to a new rate and term to see the monthly saving and how long it takes to break even.FormulaXLSXScenariosAmortizationOpen calculator FinanceAmortization Schedule CalculatorBuild a full payment-by-payment schedule showing how each instalment splits between principal and interest.FormulaXLSXAmortizationOpen calculator FinancePersonal Loan CalculatorEstimate repayments on an unsecured personal loan and see how the rate and term change what you pay overall.FormulaXLSXAmortizationOpen calculator FinanceAuto Loan CalculatorCalculate a car-loan payment from price, down payment, trade-in, rate, and term, including the total cost of financing.FormulaXLSXAmortizationOpen calculator FinanceAPR CalculatorTurn a loan rate plus fees into the true annual percentage rate so you can compare offers on equal terms.FormulaXLSXScenariosOpen calculator FinanceSavings CalculatorProject a savings balance — or solve how much to save for a goal — with monthly and annual deposits, APR/APY, tax,…FormulaXLSXChartsOpen calculator FinanceRetirement CalculatorProject your retirement pot from current savings, contributions, and growth, and gauge whether it meets your goal.FormulaXLSXChartsOpen calculator Finance401(k) CalculatorProject your 401(k) balance with employer match, 2026 IRS limits, fees, and inflation — plus a match maximiser, ear…FormulaXLSXChartsAdvancedOpen calculator EconomicsFinancial Needs Pyramid CalculatorEstimate how stable each layer of a financial needs pyramid is — from basic needs and safety to financial control,…FormulaXLSXChartsScenariosAdvancedOpen calculator InvestingROI CalculatorReturn on investment five ways — simple ROI, date-based ROI, net ROI after fees/taxes/income, a reverse target solv…FormulaXLSXChartsScenariosOpen calculator InvestingDividend Reinvestment CalculatorDRIP and dividend income six ways — full or partial reinvestment, DRIP vs cash, after-tax reinvestment, a dividend…FormulaXLSXChartsScenariosOpen calculator TaxSalary & Take-Home Pay CalculatorEstimate take-home pay five ways — a simple global gross-to-net estimate, sourced payroll models for the US, India,…FormulaXLSXScenariosAdvancedOpen calculator Budget & CreditBudget CalculatorBuild a full monthly and annual budget — simple eight-field mode or a 65-line advanced planner with per-item freque…FormulaXLSXAdvancedOpen calculator Budget & Credit50/30/20 Budget CalculatorSplit take-home pay into 50% needs, 30% wants, and 20% savings/debt payoff — then compare your real spending, get a…FormulaXLSXScenariosOpen calculator Budget & CreditNet Worth CalculatorBuild a full personal balance sheet — quick 14-field net worth or 78 detailed line items with liquidity classes, li…FormulaXLSXAdvancedOpen calculator Budget & CreditDebt Payoff CalculatorSimulate up to 20 debts month by month — snowball, avalanche, highest-payment, custom, or hybrid order vs a minimum…FormulaXLSXScenariosOpen calculator Business & EcommerceMarkup CalculatorPrice from cost across 9 modes — markup, target margin, price analysis, profit target, reverse cost ceilings, ecomm…FormulaXLSXScenariosAdvancedOpen calculator Business & EcommerceBreak-Even CalculatorA full break-even planner — units and revenue break-even, contribution margin, target profit, margin of safety, and…FormulaXLSXChartsScenariosAdvancedOpen calculator Business & EcommerceEcommerce Profit CalculatorAn ecommerce operator’s profitability dashboard — net profit per order after product costs, platform and payment fe…FormulaXLSXScenariosOpen calculator Business & EcommerceLTV:CAC CalculatorFull unit-economics tool for SaaS, ecommerce, and subscription businesses: CAC, gross-profit and discounted LTV, th…FormulaXLSXScenariosOpen calculator Business & EcommercePrice Elasticity of Demand CalculatorMeasure how demand reacts to price (midpoint & simple PED), then test the revenue and profit impact of a price chan…FormulaXLSXScenariosAdvancedOpen calculator Math & StatisticsScientific CalculatorA full scientific calculator: trigonometry in degrees or radians, natural and base-10 logarithms, powers, roots, fa…FormulaAdvancedOpen calculator Math & StatisticsPercentage CalculatorA complete percentage hub: X% of Y, what percent X is of Y, reverse percentage, increase/decrease, percentage chang…FormulaXLSXScenariosOpen calculator Math & StatisticsPercentage Change CalculatorA full percentage-change analyzer: increase/decrease, absolute change, growth multiplier, reverse change, final val…FormulaXLSXScenariosOpen calculator EconomicsDiminishing Returns CalculatorA short-run production tool: enter input-output data to get total, marginal, and average product, the point of dimi…FormulaXLSXChartsScenariosAdvancedOpen calculator EconomicsOpportunity Cost CalculatorCompare Choice A vs Choice B and see the true cost of a decision — net value, opportunity cost, explicit vs implici…FormulaXLSXScenariosOpen calculator EconomicsMarginal Utility CalculatorTurn a utility table into total utility, marginal utility (ΔTU ÷ ΔQ), and utility per dollar — find where diminishi…FormulaXLSXChartsScenariosOpen calculator EconomicsSupply & Demand Equilibrium CalculatorSolve for the market-clearing price and quantity where supply meets demand.FormulaXLSXChartsScenariosAdvancedOpen 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

Seven focused areas. Open a category for its full set of calculators.

Finance

11 tools

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

View Finance

Investing

5 tools

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

View Investing

Tax

3 tools

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

View Tax

Budget & Credit

5 tools

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

View Budget

Business & Ecommerce

7 tools

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

View Business

Math & Statistics

4 tools

Percentages, percentage change, standard deviation, variance, and dataset analysis.

View Math

Economics

5 tools

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

View Economics

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?

Free calculators across 7 categories — finance, investing, tax, budget & credit, business & ecommerce, math & statistics, and economics — covering 40 tools in total.

Are the calculators free?

Yes — every calculator is free to use, with no account, sign-in, or payment.

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.

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.