Credit Card Payoff Calculator

Calculate how many months it will take to pay off a credit card balance with a fixed monthly payment, plus total interest paid

Last updated: 2026-08-03

Current Balance

Interest Rate (APR)

Fixed Monthly Payment

Carrying a credit card balance means interest is charged on whatever you still owe, every single month -- so the size of your fixed monthly payment has an outsized effect on both how long payoff takes and how much you pay in total. Our free credit card payoff calculator simulates paying down a balance with a fixed monthly payment, using the same monthly-periodic-rate method (APR ÷ 12) that credit card issuers use to estimate payoff timelines, and shows the full month-by-month schedule -- not just a single "months remaining" number -- so you can see exactly how much of each payment goes to interest versus principal.

Credit Card Payoff Formula

O(n) simulation, capped at 100 years

i_m = B_m \cdot \dfrac{APR}{12 \cdot 100}

iₘ = interest charged in month m · Bₘ = balance at the start of month m

B_{m+1} = B_m + i_m - P

P = fixed monthly payment (repeated until the balance reaches $0)

Each month, interest accrues on the current balance at the monthly periodic rate -- the APR divided by 12 -- and the fixed payment is applied to that interest first, with anything left over reducing principal. The number of months until the balance reaches $0 is the payoff time; summing every month's interest charge gives the total interest paid. Because interest is recalculated on the new, smaller balance each month, the interest portion of the payment shrinks over time and the principal portion grows, even though the payment itself stays the same. This is a simplified model that assumes no new purchases, a fixed rate, and a payment that doesn't change -- real statements often calculate interest on a daily average balance instead, which can differ slightly, but the monthly-rate method used here is the same simplified approach many issuers and payoff calculators use to project a payoff timeline.

Use Cases

Payoff Timeline Planning

See exactly how many months (and years) it will take to clear a balance at a given payment amount.

Comparing Payment Amounts

Try a few different fixed monthly payments to see how much faster a larger payment clears the balance and cuts total interest.

Understanding Interest Cost

See the total interest that will be paid over the life of the payoff, not just the monthly charge.

Debt Payoff Prioritization

Estimate payoff time and interest cost for each card individually when deciding which balance to attack first (e.g. the avalanche or snowball method).

Frequently Asked Questions

What happens if my payment is less than the interest charge?

If a fixed payment doesn't even cover the interest accruing each month, the balance never shrinks -- it stays flat or grows, and payoff is mathematically impossible under a fixed-payment/no-new-purchases assumption. This calculator flags that case explicitly instead of showing a misleading (or infinite) payoff time.

Why does the interest portion of my payment shrink over time?

Interest is charged on the balance remaining at the start of each month, so as the balance drops, the interest charged on it drops too -- more of each fixed payment goes toward principal as payoff progresses.

Does this match the interest my card issuer actually charges?

Closely, but not exactly. Many issuers calculate interest daily on your average daily balance rather than once a month on the statement balance, which can produce a slightly different total. This calculator uses the simplified monthly-rate method (APR ÷ 12) commonly used for payoff projections.

Does this assume I stop using the card?

Yes. The calculation assumes no new purchases are added to the balance and that the payment amount and APR stay constant for the whole payoff period -- the same assumption used in the payoff-time disclosure box required on credit card statements.

Why not just pay the minimum payment?

Minimum payments are typically set low (often 1-3% of the balance) specifically to keep the balance -- and the interest charged on it -- around for a long time. A larger fixed payment shortens the payoff timeline and reduces total interest substantially, which is exactly what this calculator lets you compare.

References

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