Credit Card Payoff Calculator
Paying the minimum keeps a balance alive for years. This shows how long a fixed monthly payment really takes to clear a card, and how much of your money goes to interest along the way.
| Card balance | $ |
| Interest rate (APR) | % |
| Monthly payment | $ |
Result
Your result will appear here.
How it works
Card interest is charged on the balance you carry, month by month. Your payment clears that month's interest first; only what is left reduces the balance. Early payments are therefore almost entirely interest, which is why a card feels stuck even when you are paying every month.
The calculator runs that loop until the balance reaches zero, so it accounts for the way the interest share falls as the balance shrinks. The final payment is usually smaller than the one you set.
Formula
The loop below is what the calculator actually runs; the closed form is the quick estimate for a payment that stays constant.
- Monthly rate r = APR ÷ 12 ÷ 100
- Each month: interest = balance × r; balance = balance + interest − payment
- Estimate of months: n = −ln(1 − r × balance ÷ payment) ÷ ln(1 + r)
Worked example
A $5,000 balance at 22% APR paying $200 a month: monthly interest on the first payment is $91.67, so only $108.33 goes to the balance. The card clears in about 34 months, with roughly $1,750 of the total paid going to interest.
Assumptions
The model assumes no new spending on the card, a fixed APR for the whole period, and the payment being made at the end of each month. In practice promotional rates expire, late payments can reset a promotional APR to a penalty rate, and any new charge is added to the balance being charged interest. A card with an annual fee is not modelled.
Reading the result
The number worth acting on is not the month count but the interest column. Doubling a payment typically cuts the interest by more than half, because the balance falls faster and spends fewer months being charged. Minimum payments are designed to maximise that interest: they are set at roughly one to three percent of the balance, which slows to a crawl as the balance drops.
For general information only. Your card agreement, promotional rates and fees govern the real figures.
How to use the Credit Card Payoff Calculator
It takes a few seconds, and every figure is calculated in your browser.
- Enter the card balance.
- Enter the interest rate (APR).
- Enter the monthly payment.
- Press Calculate — the result appears in the dark panel beside the form.
- Use Copy, CSV, Share or Print under the result if you want to keep it.
Credit Card Payoff Calculator — frequently asked questions
What formula does the Credit Card Payoff Calculator use?
The loop below is what the calculator actually runs; the closed form is the quick estimate for a payment that stays constant. Monthly rate r = APR ÷ 12 ÷ 100 Each month: interest = balance × r; balance = balance + interest − payment Estimate of months: n = −ln(1 − r × balance ÷ payment) ÷ ln(1 + r)
How does the Credit Card Payoff Calculator work?
Card interest is charged on the balance you carry, month by month. Your payment clears that month's interest first; only what is left reduces the balance. Early payments are therefore almost entirely interest, which is why a card feels stuck even when you are paying every month. The calculator runs that loop until the balance reaches zero, so it accounts for the way the interest share falls as the balance shrinks. The final payment is usually smaller than the one you set.
What assumptions and limitations should I know about?
The model assumes no new spending on the card, a fixed APR for the whole period, and the payment being made at the end of each month. In practice promotional rates expire, late payments can reset a promotional APR to a penalty rate, and any new charge is added to the balance being charged interest. A card with an annual fee is not modelled.
Can you walk through a worked example?
A $5,000 balance at 22% APR paying $200 a month: monthly interest on the first payment is $91.67, so only $108.33 goes to the balance. The card clears in about 34 months, with roughly $1,750 of the total paid going to interest.
Last updated 10 November 2026 · Formula, worked example and assumptions are documented above, and every result is calculated in your browser.