Debt Payoff Calculator
See when you will be debt-free, the total interest and how much extra payments save, for one debt or up to five using the avalanche or snowball method, with a payoff order and schedule.
How it works
Months = log(payment ÷ (payment − balance × r)) ÷ log(1 + r), where r = APR ÷ 12 · Several debts: each month every debt gets interest and its minimum; the rest of the budget goes to the target debt (avalanche = highest APR, snowball = smallest balance) · Goal payment = balance × r ÷ (1 − (1 + r)^−n)
Each month interest is charged on what you still owe, your payment covers that interest first, and the rest lowers the balance. If the payment is only a little above the monthly interest, payoff drags on for years. An extra payment goes straight to principal, so it shortens the payoff and cuts total interest, and it helps most at the start when the balance is highest. With several debts, the calculator pays every minimum, sends the extra money to one target debt, and when that debt is gone moves its payment to the next one (the "rollover"). The avalanche method targets the highest APR first and saves the most interest; the snowball method targets the smallest balance first, so you close accounts sooner. The comparison table runs all methods side by side, and the payoff-order table shows when each debt is cleared. You can also add a yearly lump sum (such as a tax refund) or a one-time payment, and set a debt-free goal to see the monthly payment it takes.
Worked example
An $8,000 balance at 22% APR paid at $250 a month takes 49 months and $4,158 of interest. Adding $100 (to $350 a month) clears it in 30 months with $2,463 of interest, saving about $1,695 and 19 months. To be debt-free in 24 months you would pay $415.03 a month. With three debts — $8,000 at 22% ($250 minimum), $3,500 at 18% ($100) and $12,000 at 7% ($280) — and $100 extra, the avalanche method pays $730 a month and is debt-free in 40 months (3 years 4 months) with $5,470 of interest: the 22% debt is gone in month 30, the 18% debt in month 34 and the 7% loan in month 40. The snowball order finishes in the same 40 months but costs $5,675, and minimum payments alone take 50 months and $7,506.
Sources: CFPB — How to reduce your debt (snowball and highest-interest-first methods) · CFPB — Reducing debt worksheet (Your Money, Your Goals)
Frequently asked questions
Avalanche or snowball — which should I use?
Avalanche (highest APR first) always costs the least interest or ties. Snowball (smallest balance first) clears whole accounts sooner, which many people find motivating. Pick both in the calculator: the comparison table shows the difference in months and interest for your own debts, which is often small.
Why do small extra payments help so much?
Extra money goes entirely to principal, which lowers every later interest charge. On high-APR debt this adds up to large savings and a much shorter payoff.
What does rolling over a payment mean?
When a debt is paid off, you keep paying the same total and move its old minimum payment to the next debt. That is what makes snowball and avalanche plans fast. Turn rollover off under More options to see what happens if you let the total payment fall instead.
What if my payment barely covers the interest?
The balance shrinks very slowly and payoff can take decades. Only the amount above the monthly interest lowers the debt. The calculator warns you when a minimum payment doesn’t cover a debt’s interest.
How much do I need to pay to be debt-free by a certain date?
Enter the number of months under "Debt-free goal". For one debt the calculator uses the loan payment formula; for several debts it finds the smallest steady total payment that clears all of them in time with your chosen method.
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This is an educational estimate, not financial advice. Confirm figures with your lender, advisor or tax professional.