Debt Payoff Calculator

How this debt payoff calculator works

This simulator answers a practical question: if I owe a balance at a given APR and I pay a fixed amount every month, how long until the debt is gone, and how much will I pay in total? It is useful for credit cards, store cards, and other revolving balances where you choose the payment rather than locking a fixed installment schedule.

Month-by-month logic

Each month, interest is applied to the remaining balance using the annual rate divided by 12. Your payment first covers that interest; anything left reduces principal. The process repeats until the balance reaches zero (or until a safety limit of months is hit if the payment is too small to cover interest).

Worked example (dollars)

Imagine $4,000 owed at 22% APR with a $200 monthly payment. Early months send a large share of the payment to interest. As principal falls, more of each payment reduces the balance, so payoff accelerates. If you raise the payment to $300, months to payoff and total interest both drop sharply — that tradeoff is exactly what this tool is meant to show.

Illustrative UK / Europe example (£)

Illustrative planning example only — not credit advice. Credit-card APRs and minimum-payment rules vary by issuer and country.

Suppose a revolving balance of £3,500 at 19.9% APR. Compare a fixed payment of £120 per month with £180 per month in the form above. The higher payment usually cuts both months-to-zero and total paid, because fewer months of interest accrue. If the tool warns that the payment never pays off the debt, the £120 (or whatever you entered) is not covering monthly interest — raise the payment or lower the APR assumption.

How to use it

1. Enter your current balance (what you owe today).
2. Enter the APR as an annual percent.
3. Enter the fixed monthly payment you can sustain.
4. If the tool warns that the payment does not cover interest, increase the payment or lower the rate assumption.

Tips for payoff planning

• Paying more than the minimum usually cuts years and interest cost.
• A 0% promotional APR still needs a plan for when the promo ends.
• New charges increase the balance; this model assumes you stop adding to the debt.

Decision checklist

• Stop new charges — A payoff plan that assumes a fixed balance fails if the card is still used for everyday spending.
• Payment vs interest — If the warning appears, the plan is not a payoff plan yet.
• Extra £50–£100 — Re-run with a modest increase; compare months and total paid.
• Multiple cards — Run one target debt here while paying minimums elsewhere; see snowball vs avalanche for order.

Frequently asked questions

Why does it say my payment never pays off the debt?

If the monthly payment is less than or equal to the interest accruing that month, the balance does not fall. Raise the payment or lower the rate assumption.

Is this snowball or avalanche?

This page models a single balance. For multiple debts, choose an order (smallest balance or highest rate) and apply extra payments deliberately. Our guide on debt snowball vs avalanche walks through both rules with a worked multi-card example.

What “paying extra” actually changes

On high-APR revolving debt, a modest increase above the interest-covering payment shortens the timeline disproportionately because later months stop existing. Try your real balance twice: once at the payment you make today, once with £50–£100 (or $50–$100) more. Compare months-to-zero and total paid — that gap is often the most persuasive argument for cutting discretionary spending or pausing new charges.

If you hold several cards, run this calculator once per target debt while you pay only minimums elsewhere. When the first target hits zero, rerun the next debt with the rolled payment. That is the operational core of both snowball and avalanche plans.

Why the last payment is usually smaller

At 0% interest, a balance of 1,000 with payments of 300 takes four months: 300 + 300 + 300 + 100. Total paid is 1,000, not 1,200. This calculator caps the last payment at the remaining balance plus that month’s interest.

For interest-bearing balances, each month first adds balance × APR ÷ 1,200, then subtracts the actual payment. No new purchases or fees are added. The simulation stops after 1,200 months rather than presenting an unsupported payoff date.

Limitations

Late fees, penalty APRs, and changing rates are not included. Results are estimates only and are not financial advice.

Results are estimates only and are not financial advice.