Credit Card Interest Calculator

See how much interest your credit card balance costs you each month and per year at your APR.

Interest this month

$91.67

Interest per year (at this balance): $1,100
Of your payment goes to interest: $91.67
Of your payment reduces the balance: $58.33
Payoff time at this payment: 4 yr 4 mo
Total interest paid: $2,798

Interest this month$91.67

Results are estimates for planning and are not financial advice.

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Quick answer

A $5,000 balance at 22% APR costs about $92 in interest this month — a $150 payment only reduces the balance by about $58.

How it works

Credit card interest is your balance times your APR divided by 12, charged monthly. If your payment only covers the interest, your balance never shrinks — even a little extra goes straight to principal.

Formula

Monthly interest = Balance × (APR ÷ 12)

Assumptions & limitations

Fixed APR
No new purchases added to the balance
Payment stays the same every month

Formula and assumptions reviewed October 2026 by the Calculyn team. How we build our calculators

Frequently asked questions

When is interest charged?

Interest applies when you carry a balance past the due date. Paying in full each month usually means zero interest.

Is APR the same as interest rate?

For credit cards, yes — the APR is the annual rate, and issuers divide it by 12 (or 365) to charge you monthly or daily.