Credit Card Calculator
Enter your card balance, its APR and the amount you will pay each month. The calculator works through the payoff one month at a time and shows how many months it takes, the total interest and the total you pay. It assumes the same payment every month, no new purchases and no fees.
How to use the Credit Card Calculator
- Enter your numbers in the Credit Card Calculator above.
- Press the Calculate button to see the result.
- To try other numbers, change any value and press the button again.
How the payoff is worked out
Each month: Interest = Balance × APR / 12, rounded to the cent · · · New balance = Balance + Interest − Payment
The calculator repeats this until the balance reaches 0 and counts the months. The last payment is whatever is left, so it is usually smaller than the others, and the page shows it under the result. Total paid is every payment added up, the last one included, and total interest is total paid minus the starting balance. At 0% APR the balance falls by the payment each month. If the payment is no more than the first month's interest, the balance never goes down and the page says so. Your card issuer may work out interest differently, for example on a daily balance, so its figures can differ.
Worked example
A $6,000 balance at 21% APR with $150 a month takes 70 months to pay off. The first 69 payments are $150 and the last is $60.21, so you pay $10,410.21 in total, of which $4,410.21 is interest. At $300 a month the same card is paid off in 25 months with $1,449.66 of interest.
Frequently asked questions
Does the calculator handle minimum payments?
No. It keeps the payment the same every month. A minimum payment that shrinks as the balance falls stretches the payoff and adds interest, and the calculator cannot follow that. Enter the fixed amount you plan to pay.
What APR am I likely to have?
Your own APR is printed on your monthly statement. For comparison, the Federal Reserve's G.19 Consumer Credit release put the average rate on credit card accounts assessed interest at 22.15% in the second quarter of 2026, and 20.94% across all accounts.
Can I check a balance transfer?
Roughly. Add the transfer fee to the balance, enter the promotional APR, such as 0%, and compare the result with your current card. The calculator applies one rate to the whole payoff. If the promotion ends before the card is paid off, the real interest will be higher than it shows.