Debt Payoff Calculator

The $171 that separates avalanche from snowball

Take three cards: $4,000 at 24% (minimum $120), $2,500 at 29% (minimum $80), and $1,500 at 19% (minimum $50), with $200 a month extra and freed-up minimums rolling forward. Avalanche aims the extra at the 29% card first; snowball aims it at the $1,500 balance first; both plans finish in 23 months. The only thing that differs is the interest — $1,933 under avalanche against $2,104 under snowball. The entire price of choosing motivation over arithmetic here is $171, roughly 8% of the snowball interest bill ($171 ÷ $2,104), spread across nearly two years.

That is the number the comparison table exists to produce, and it is the number that should settle the argument rather than a rule of thumb repeated from somewhere else. Avalanche pays every minimum and aims all spare money at the highest APR; with fixed rates it is the cheapest possible order, because interest is charged per unit of balance per month and the highest rate destroys the most money per unit held. Snowball pays every minimum and aims the extra at the smallest balance; it closes whole accounts fastest at the start, which is worth something real that no interest total captures. Neither is an official method. No law, regulator or standards body defines either ordering, and the consumer regulator that sets the two out side by side explicitly presents them as a choice between trade-offs rather than naming a winner — which is exactly how they are treated here.

What decides the size of the gap is the APR spread, not the balances. In this example the rates run from 19% to 29%, a ten-point spread, and the gap is $171. Squeeze the rates together and the gap collapses toward zero: if every debt carried the same APR, the two orders would cost identical interest to the cent and snowball would be free. Widen the spread and the gap grows, because every month the extra sits on a lower-rate debt is a month the highest rate compounds untouched. An expiring promotional APR can reorder the answer outright, since the debt that is cheapest today may be the most expensive eight months from now. That is why the comparison runs on your actual balances and rates instead of asserting a general winner.

Read the two gaps together. The interest gap is what the choice costs. The first-win gap is what it buys — how many months sooner an account closes for good. When the interest gap is small, which is common when your APRs are clustered, buy the early wins; the behavioural benefit is not imaginary and the arithmetic is barely arguing. When one debt sits far above the rest, let the arithmetic win. Both gaps are measured against the minimum-only baseline, which on these three cards runs 59 months and $5,423 of interest. Paying the extra $200 therefore saves 36 months and $3,490 ($5,423 − $1,933) — more than twenty times the $171 either strategy can win or lose. Choosing between avalanche and snowball is the second decision. Paying more than the minimums is the first, and it is not close.

Why the first $250 in minimums moves your balance by $86

Everything on this page comes out of one loop repeated up to 600 times, and the loop is short enough to check by hand. Each month, every debt accrues interest on its current balance, any monthly fee is added, the minimum comes off, and whatever extra the strategy has assigned to that month’s target debt comes off as well. A debt payoff calculator is mechanically nothing more than that loop run forward until every balance reaches zero, reporting the month it happens and the interest it cost on the way.

Put the three cards above through a single turn of that loop. The $4,000 balance at 24% accrues $4,000 × 0.24 ÷ 12 = $80.00. The $2,500 at 29% accrues $2,500 × 0.29 ÷ 12 = $60.42. The $1,500 at 19% accrues $1,500 × 0.19 ÷ 12 = $23.75. Month one therefore costs $164.17 in interest against $250 of minimum payments, so $85.83 — barely a third of the money you handed over — actually reduced what you owe. Add the $200 extra and the arithmetic inverts: $450 leaves your account, the same $164.17 still evaporates, and $285.83 lands on principal. The extra $200 did not buy $200 of progress. It bought more than three times the progress the minimums alone were making, because it is the only part of the payment that meets no interest on its way in.

That ratio is why minimum payments feel like running on sand, and why the debt-free date is far more sensitive to the extra amount than to the ordering. It also explains the shape of every schedule row below the calculator: as balances fall, the interest column shrinks, so the same fixed payment quietly buys more principal each month than it did the month before. Progress accelerates on its own once it starts — which is precisely the effect the minimum-only baseline denies you, month after month, for years.

Two mechanical details matter when you read a row. Payments are capped at the balance, so a debt never overshoots into a negative number and the final payment is simply whatever is left. And a promotional APR applies only through the end month you set, after which that debt reverts to its standard rate for every remaining month. A plan that looks comfortable on a 0% promo can change character sharply on the month it expires, and checking where that month falls is worth doing before you commit to an order.

When a debt clears, its payment either rolls forward or evaporates

The single switch that moves your debt-free date the most is not the strategy dropdown. It is the fixed-total toggle: the decision about what happens to a minimum payment on the day the debt it belonged to reaches zero.

With the toggle on, your total monthly outlay stays constant. Clear the $1,500 card and its $50 minimum does not return to your spending — it joins the $200 extra and attacks the next target, so the money aimed at that debt jumps from $200 to $250 without you finding another dollar anywhere. Clear the next debt and its minimum joins too. This is the roll-down, and it is exactly the mechanic the official debt worksheets describe: after every minimum is paid, increase the payment on one chosen debt, then move that whole amount to the next debt once the first one clears. It is also why the word snowball exists at all. The thing that grows is the payment, not the balance.

With the toggle off, the freed minimum simply leaves the plan. Your total payment drops by $50 the month that card closes, and every remaining month is slower and dearer than it would have been. That is the honest setting if you know the money is already spoken for — a rent increase, a childcare bill, a raise you have committed elsewhere — and modelling what will actually happen beats modelling a discipline you will not have. But run it both ways before choosing. The gap between rolling forward and letting payments fall is usually much larger than the gap between avalanche and snowball, because it changes the size of the payment rather than only its destination.

The scheduled extras obey the same logic. A yearly bonus month, a one-time lump sum, and a limited-time recurring extra are each applied in the specific month you name, to that month’s target debt, and they all compound in the same direction: money that arrives early has more months left in which to stop interest accruing than the identical money arriving late. A $1,000 lump sum in month three and a $1,000 lump sum in month thirty are not the same plan, and the schedule will show you how far apart they are.

Working backward from a date makes the payment the unknown

Most of this page answers one question: when will I be free if I pay this much a month? The debt-free-by-date solver answers the reverse — what does the payment have to be, if free has to mean by a particular month? It is the same simulation with a different unknown, and it is usually the more useful direction whenever the deadline is real: a lease ending, a mortgage application, a move, a job change.

What it returns is the total monthly payment your chosen strategy needs in order to land on or before that month, given the balances, APRs, minimums and fees you entered. Ordering still matters here, so the required payment is not identical under every strategy: the cheaper order needs slightly less money to hit the same date, because less of each payment is being burned as interest along the way. Solve under avalanche, then under snowball, and the difference between the two figures is the monthly price of the ordering you would rather have.

Two outcomes are worth expecting. The solver can return a payment you cannot make, which is information rather than failure — it tells you that the date has to move, the rates have to change, or something else in the budget does. And it can return a payment barely above what you already pay, which usually means the deadline was never the binding constraint and you were closer than you thought. Either way, treat the figure as a floor rather than a plan. It assumes no new borrowing, no missed months, and no penalty rates, and each of those pushes the real requirement upward.

“Never” is an answer this calculator is willing to give

If a payment is smaller than the month’s interest, the balance grows. Nothing in the arithmetic prevents it, and hiding it would be the single most damaging thing a payoff planner could do. On the $4,000 balance at 24% above, one month of interest is $80 — so any minimum below $80 on that card leaves you owing more at the end of the month than at the start, forever, however many months you add. The stated minimum of $120 clears that bar by $40, and that margin is the only reason the debt amortizes at all.

When it does not, this page flags the debt and reports “Never (not amortizing)” instead of manufacturing a date. The simulation itself stops at 600 months — fifty years — and anything still outstanding at that point is reported as not amortizing rather than dressed up as a fifty-one-year plan. A date you cannot act on is worse than an admission, because it invites you to keep going on terms that cannot work.

The flag often appears on the minimum-only baseline even when your chosen strategy finishes comfortably, and that contrast is the comparison at its most useful: it is the difference between a plan and a treadmill. Fixing a never-amortizing debt takes one of exactly three things — a larger payment, a lower rate, or the lender changing the terms. Rearranging the order of your debts cannot do it, and neither can this calculator. If the payment cannot rise and the rate cannot move, that is the moment a qualified nonprofit credit counsellor or a licensed professional is the right next call, rather than another spreadsheet.

Student loans, credit cards and consolidation each break a different assumption

Fifteen debt types can be selected here — credit card, personal loan, auto loan, mortgage, student or education loan, medical debt and others — and the label changes how a debt is grouped and reported, not how it is simulated. Every debt is amortized the same way: your payment, your rate, interest once a month. That is the right model for most consumer debt and the wrong model for three cases in particular.

Student loans fit only while repayment is a fixed monthly amount at a fixed rate. Income-driven repayment plans, forgiveness programmes, subsidised-interest periods and deferment follow statutory rules that sit outside standard amortization, and none of them are modelled here. Simulate the fixed-payment version if that is genuinely what you pay each month; for anything else, the programme rules govern and this projection will drift from them.

Credit cards fit while you treat the minimum as a fixed number you have chosen. Real issuers recalculate the minimum every statement by formula — typically a percentage of the balance plus interest and fees — so the required payment falls as the balance falls, which is the exact mechanism that stretches card debt across decades. If credit cards are all you are paying off, the credit card payoff calculator is the more precise tool: it models issuer-style recalculating minimums, credit utilization, promotional APRs and balance transfers. Use this page when those cards sit alongside loans, medical bills and other debts inside one plan.

Consolidation is a different question, and this page deliberately declines to answer it. Replacing several debts with one new loan can lower the blended rate and simplify the month, or it can quietly cost more through origination fees, a longer term, or balances you re-borrow onto the cards you just cleared. Model both sides with the same debts on the debt consolidation calculator, which compares paying them separately against a single new loan. To fit the payment into the rest of your month, use the budget calculator; to compare the true cost of any replacement borrowing, use the APR calculator.

Four boundaries hold across all three of those cases, and across every plan this page produces:

• Not a lender payoff quote — the official payoff amount on any date comes from your lender.
• Lender rules, compounding, fees, taxes, minimum-payment formulas, and legal remedies vary by country.
• No strategy is universally best for behaviour; the comparison shows costs so you can choose deliberately.
• No consolidation, settlement, refinancing, or bankruptcy advice — those are separate decisions for qualified humans.

Why your lender’s payoff figure will not match this one

Ask a lender for a payoff amount and you get a number to the cent, valid until a stated date. This page cannot produce that number and does not try to. What it produces is a projection built on five stated assumptions, and the distance between the projection and the quote is the sum of exactly those five things:

• Interest accrues monthly at APR ÷ 12 on the current balance; actual cards may accrue daily and differ slightly.
• Minimum payments are the amounts you enter and stay constant; real lender minimums often recalculate monthly by formula.
• Optional monthly fees are added to the balance before interest; promotional APRs apply through their end month, then revert.
• No new purchases, charges, or borrowing are assumed. Payments are on time; late fees and penalty APRs are not auto-modeled.
• The simulation caps at 600 months; anything longer reports as not amortizing rather than a fake date.

The widest of those gaps is usually accrual. Interest here is charged once a month at APR ÷ 12 on the balance at the start of the month, while many credit cards accrue daily on an average daily balance — a small difference that compounds slowly across a long plan. The second widest is the minimum payment, which this model holds at whatever you typed while your issuer recalculates it every statement. Neither difference changes which strategy is cheaper or roughly when you finish. Both mean the final month will not land on the exact cent shown here, which is why you confirm the real figure with each lender before acting on it.

These limitations are structural rather than defects, and they are worth stating plainly. This is not a lender payoff quote. It is not advice on consolidation, settlement, refinancing or bankruptcy. It does not know your country’s rules on compounding, fees, taxes, statutory minimum-payment formulas or legal remedies, all of which vary. And it cannot see anything you do not enter — a missed payment, a penalty APR triggered by one late month, a new purchase on a card you are paying down. Any of those resets the plan, and re-running it with the real numbers is far cheaper than pretending it did not happen.

Everything runs in your browser, so nothing you type is sent anywhere or stored. Amounts are unit-agnostic: choose INR, GBP, EUR, CAD, AUD, AED, SGD or JPY, or set a custom symbol for any other currency, and the arithmetic is identical because the model never converts between currencies. The export is a standard 10-sheet XLSX workbook with live formulas — Excel opens it directly, and Google Sheets converts it natively through File then Import, or by uploading it to Drive. Take that schedule to your lender, or to a counsellor, and check it line by line against the figure they give you.

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Read the guides

For the full comparison of snowball vs avalanche, with worked numbers, see Debt Snowball vs Debt Avalanche: How to Compare Payoff Methods.

To see how this debt load weighs against your income, see What Is a Good Debt-to-Income Ratio and How to Calculate It.

Sources and methodology

Snowball and avalanche are popular heuristics, not official methods. No law, regulator or standards body defines either ordering, certifies one as correct, or endorses it over the other. The consumer regulator sets the two out side by side as a choice between trade-offs and leaves the decision to you, and that is the only sense in which it is cited below.

What this page does is arithmetic: it amortizes each balance at the APR you enter, applies the minimum payments, and rolls a freed-up payment into the next debt in whichever order you pick - entirely in your browser. No lender data is fetched, no rates are looked up, and nothing here is a payoff quote, so confirm the real figure with each lender before acting on it. The sources below cover the mechanics that do have an authority behind them: the official debt worksheets these inputs mirror, the legal definition of APR, and the published average rates to check your own against. Links open in a new tab.

• How to reduce your debt - the regulator setting out the two orderings this calculator implements, highest interest rate first and smallest balance first, explicitly as a choice between trade-offs rather than as a recommended methodConsumer Financial Protection Bureau (CFPB) · verified 2026-09-01
• Reducing debt worksheet (Your Money, Your Goals, Tool 3) - the official worksheet that orders debts either by interest rate or by amount owed, records the amount still owed, the monthly payment and one extra payment per debt, then moves the whole payment to the next debt once one clears: the same ordering choice and roll-down this calculator runsConsumer Financial Protection Bureau (CFPB) · verified 2026-09-01
• Debt action plan tool - the official description of the mechanic this calculator models (after every minimum is paid, increase the payment on one chosen debt, then add that amount to the next when it clears), and the regulator statement in the same document that neither ordering is better than the otherConsumer Financial Protection Bureau (CFPB) · verified 2026-09-01
• Regulation Z, 12 CFR 1026.22, Determination of annual percentage rate - the legal definition of the APR you enter for each closed-end debt such as an auto, student or personal loanConsumer Financial Protection Bureau (CFPB), Regulation Z · verified 2026-09-01
• G.19 Consumer Credit release - published average APRs on credit card accounts and new-car loans, the benchmark to sanity-check the rates you enter for each debtBoard of Governors of the Federal Reserve System · verified 2026-09-01