Debt Payoff Calculator: Avalanche vs Snowball
Work out how long a debt takes to pay off and the interest it costs, the payment that clears it by a target month, or the best order to pay off up to ten debts with the avalanche or snowball method.
Interest is estimated monthly at APR/12 on the balance before each payment, with no fees, promotional rates or daily balances. The results are estimates.
Fix the highlighted fields to see the plan.
About the Debt Payoff Calculator
The Debt Payoff Calculator shows how long your debts take to pay off, how much interest they cost and the month you become debt-free. It has three plans. One debt, fixed payment takes a balance, an APR and what you pay each month, and shows the number of payments, the total interest, the total paid and the month of the last payment. One debt, target month works the other way: pick the month you want to be debt-free and it shows the equal monthly payment that gets you there. Several debts takes up to ten debts, each with a balance, an APR and a minimum payment, and one monthly budget, and compares the avalanche and snowball methods side by side.
Interest is estimated monthly at APR ÷ 12 on the balance before each payment, with no fees, promotional rates or daily balances. Card issuers usually charge on the average daily balance, so the results are estimates, but they are close enough to plan with.
How to use it
One debt
- Choose One debt, fixed payment or One debt, target month.
- Type the balance and the APR.
- Type your monthly payment, or pick the month of your last payment. The first payment month starts at the current month; change it if you start later.
Several debts
Choose Several debts, fill in one row per debt and type the total you can pay each month across all of them. Press Add a debt for more rows, up to ten. The calculator pays every minimum first, then puts the rest on one debt at a time, and shows each method's debt-free month, total interest and the month each debt clears.
The formulas
Each month, a balance at an annual rate earns interest of
and then the payment is taken off. The equal payment that clears a balance in months at the monthly rate is
With several debts, avalanche puts the spare money on the highest APR first and snowball on the smallest balance first. When a debt is cleared, its minimum rolls on to the next one.
Worked examples
- One card at a fixed payment. 5,000 at 18% APR paid at 200 a month takes 32 payments and costs 1,313.96 in interest. Starting in November 2026, the last payment falls in June 2029.
- A loan you can check. 10,000 at 5% paid at 200 a month takes 57 payments and 1,236.92 of interest, the same as the Loan Calculator.
- A target month. To clear 5,000 at 18% in 24 payments, pay 249.62 a month; the interest is 990.89.
- Three debts. Card A (3,000 at 22%, minimum 90), Card B (1,000 at 18%, minimum 30) and a car loan (6,000 at 6%, minimum 150) with a budget of 500: avalanche costs 938.31 of interest and snowball 971.14, and both are debt-free in month 22.
Related calculators
For one loan with an amortization schedule and extra payments, use the Loan Calculator. To see how the money you free up could grow once you are debt-free, use the Compound Interest Calculator.
Privacy
Nothing is uploaded; every calculation runs in your browser and never leaves your device. The balances you type stay on this page and are gone when you close or reload it.
Frequently asked questions
How is the payoff time worked out?
Each month the calculator adds interest of balance × APR ÷ 12 and then takes off your payment, until the balance reaches zero. 5,000 at 18 percent APR paid at 200 a month takes 32 payments and costs 1,313.96 in interest.
What is the difference between the avalanche and snowball methods?
Both pay the minimum on every debt and put the rest of the budget on one debt at a time. Avalanche picks the highest APR first, which costs the least interest. Snowball picks the smallest balance first, which clears a debt sooner and can keep you motivated.
What happens when one debt is paid off?
Its minimum payment stays in the budget and rolls on to the next debt in the chosen order. That is why the payments seem to snowball: each cleared debt frees more money for the next one.
How do I find the payment needed to be debt-free by a date?
Choose One debt, target month and pick the month of your last payment. The calculator counts the first and last months as payment months and uses the loan formula P × r ÷ (1 − (1 + r)^−n). 5,000 at 18 percent over 24 months needs 249.62 a month.
Why does it say my payment never pays off the debt?
If the payment is no more than the first month's interest, the balance never goes down. At 24 percent APR, 5,000 earns 100.00 of interest a month, so a payment of 100.00 only covers the interest. Pay more than that to make progress.
Why might my lender's figures differ?
Card issuers usually charge interest on the average daily balance and round to the cent, and they can add fees or promotional rates. This page charges interest monthly at APR ÷ 12, so its results are estimates that are usually within a few cents to a few dollars.