By Meraj Uddin Provat · Last reviewed May 23, 2026 · Editorial Standards
A debt balance has two clocks running against it: the payment you make and the interest the lender adds back. Whether you ever get to zero — and how fast — depends entirely on which clock is winning. This calculator shows the finish line for your numbers and what one extra payment does to it.
Debt Payoff Calculator
How long until the balance hits zero — and what an extra payment does to it. Updates as you type.
Assumes a fixed APR and a constant payment applied monthly, interest accruing on the remaining balance. Real card/loan terms, fees and variable rates differ. Estimates only, not financial advice.
How to use this calculator
Enter the balance, the APR, and the monthly payment you actually make. Add an optional extra amount on top. The result is your debt-free date, the total interest you will pay, and a side-by-side of what the extra payment saves versus paying only the base amount.
The one rule that decides everything
Each month the lender adds interest on the remaining balance. Your payment first covers that interest; only what is left over reduces the balance. So the test is simple: your payment must exceed the monthly interest, or the balance never falls. On a $12,000 balance at 22% APR, monthly interest alone is about $220 — pay $200 and the debt grows forever. The calculator flags this explicitly because it is the most common reason payoff “never happens.”
Why extra payments are so powerful
Every extra dollar skips the interest line entirely and lands on principal. Because it reduces the balance for every remaining month, the saving compounds: the earlier and larger the extra payment, the more future interest it erases. This is why a modest, consistent extra amount often cuts months — sometimes years — off a payoff and saves a striking amount of interest.
High rate first: the avalanche idea
If you carry more than one debt, send every spare dollar to the highest-APR balance while paying minimums on the rest. That order removes the most expensive interest first and costs the least overall. The popular alternative — smallest balance first — can help motivation, but it is the more expensive route. Run each debt here separately to see the spread.
How to get to zero faster
- Pay more than the interest, always — that is the non-negotiable floor; anything below it is treading water.
- Add a fixed extra amount — even a small steady extra compounds into a large interest saving.
- Attack the highest APR first — the avalanche order minimizes total cost.
- Avoid new charges on the same balance — new spending resets the progress the extra payment just bought.
- Lower the rate if you can — a balance transfer or consolidation drops the interest line, but only helps if you stop adding to the balance.
Frequently asked questions
Why does my balance barely move at first? Early payments are mostly interest because the balance — and the interest charged on it — is at its largest. As principal falls, more of each payment attacks the balance and progress accelerates.
What if my payment is below the monthly interest? The balance grows instead of shrinking and the debt never pays off. You must pay more than the monthly interest charge for any progress at all.
Avalanche or snowball — which is better? Highest-APR-first (avalanche) costs the least in total interest. Smallest-balance-first (snowball) can be more motivating but is usually more expensive.
Does a balance transfer help? It can, by cutting the interest line — but only if you stop adding new charges and pay it down during the low-rate window. Watch transfer fees.
Is this exact for credit cards? It is a close planning model. Real cards use daily compounding, fees, and changing minimums, so treat the output as a strong estimate, not a statement.
Methodology
The payoff is simulated month by month: interest accrues on the remaining balance at the monthly rate, the payment is applied, and the remainder reduces principal until the balance reaches zero. If the payment never exceeds the monthly interest, the tool reports that the debt does not pay off. The comparison runs the same simulation with and without the extra payment to show months and interest saved. Fixed APR and constant payment are assumed. Estimates only, not financial advice.
Written by the CalcCottage team. We show the real number, not the marketing number.