This calculator shows what your credit card balance actually costs you (per day, per month, and per year) at your card’s APR. If you carry a balance, this is what it costs to hold it.
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How card interest actually works
Card issuers divide your APR by 365 to get a daily periodic rate, apply it to your average daily balance, and compound it. Two things follow from that. First, interest accrues every day you carry a balance. Second, if you pay your statement balance in full by the due date, most cards charge no interest at all, because of the grace period on purchases. The deciding factor is which side of that line you are on.
The figures above use the standard monthly approximation (balance × APR ÷ 12). Your statement may differ slightly because of daily compounding and balance changes during the cycle. Wondering how your rate compares? See the current average card APR, tracked live from Federal Reserve data.
Paying more than the monthly interest
Every dollar you pay above your monthly interest cost reduces your balance; every dollar below it grows the debt. To see your actual payoff timeline at a given payment, use the card payoff calculator. If the interest cost is high and your credit is damaged, a lower-rate debt consolidation with bad credit loan or a balance transfer with bad credit can reduce the rate you pay.
Frequently asked questions
Is APR the same as interest rate on a credit card?
For purchases, effectively yes — a card’s purchase APR is the annualized rate applied daily. Cards can carry separate, higher APRs for cash advances and penalty situations.
How do I avoid credit card interest entirely?
Pay the full statement balance by the due date every month. The grace period means purchases charged this cycle cost you nothing in interest — carrying even $1 forward forfeits it on most cards.
Why did I get charged interest after paying my balance?
Usually trailing interest (“residual interest”): interest that accrued between your statement date and the day your payoff payment arrived. Ask your issuer for a payoff quote instead of paying the statement number.