Debt Payoff Calculator (2026)
Enter your current balance, annual interest rate, and the fixed amount you can pay each month. This calculator estimates how many months until you are debt-free and the total interest you will pay. Everything runs in your browser; nothing is stored or sent anywhere.
Estimate updates as you type. Assumes a fixed rate and the same payment every month until the balance reaches zero.
How the debt payoff estimate works
The calculator models your debt one month at a time. Each month it adds interest equal to your annual rate divided by twelve, then subtracts your fixed monthly payment. It repeats this until the balance hits zero, counting the months and adding up the interest. The faster you can pay above the monthly interest charge, the sooner the balance falls and the less interest you pay in total.
If your payment is too small to cover even the monthly interest, the balance never shrinks and the debt is never paid off. The calculator detects this and shows a warning instead of an impossible answer.
Snowball vs. avalanche, briefly
When you juggle several debts, two popular strategies decide which to attack first. The avalanche method targets the highest interest rate first and usually costs the least overall. The snowball method targets the smallest balance first for quick motivational wins. This tool models a single balance with a fixed payment, so you can use it for one debt or a combined total to see the big-picture timeline.
Common questions
Why must my payment exceed the monthly interest?
If the payment only covers (or fails to cover) the interest added each month, the principal never goes down. Raising the payment, even a little, can dramatically shorten the payoff time and cut total interest.
Does this include fees or penalties?
No. It assumes a fixed rate and a constant payment, and ignores late fees, penalty APRs, and promotional rates. Treat the result as a clean estimate and check your real terms with your lender.
Is my data saved?
No. The calculation runs entirely in your browser. Nothing you type is stored, transmitted, or shared.
Method: simulates the balance month by month, adding interest at the annual rate divided by twelve and subtracting a fixed monthly payment until the balance reaches zero. General references include published explainers on debt payoff, the snowball method, and the avalanche method from NerdWallet, Bankrate, and Investopedia. This is educational information, not financial advice.