Credit card interest calculator
Estimate repayment for one balance at a fixed APR. Compare monthly payments, extra payments and an editable illustrative minimum rule.
Interest on this balance
Enter your balance, APR and monthly payment, then calculate. Hourly pay is optional.
The labeled example uses $5,000 at 24% APR, a $150 payment, $50 extra and $25/hour take-home pay, starting January 31, 2026.
Fixed-APR monthly estimate: cent-rounded interest posts before payment; the final payment is capped. No new purchases, fees, promotions or grace periods are modeled. The illustrative minimum rule is an editable assumption.
Many issuers use daily average balances, so this estimate cannot reconstruct your statement. Sources: CFPB interest explanation and CFPB repayment disclosure rules, accessed October 11, 2026.
Monthly estimate
Each month, interest is opening balance × APR ÷ 1200, rounded half up to cents. That interest is added before the payment; the final payment is capped at the amount owed. Each scenario runs independently for at most 1,200 months.
No new purchases, fees, promotions or grace periods are included. Many issuers use average daily balances. Your statement and required minimum can differ from this fixed-month model.
Worked example: $5,000 at 24% APR
A $150 fixed payment pays off this model in 56 months: $3,322.17 interest and $8,322.17 paid. Paying $200 instead takes 36 months: $2,000.57 interest and $7,000.57 paid. The extra $50 saves 20 months and $1,321.60 interest.
Initial posted monthly interest is $100. The separate daily snapshot is unrounded balance × (APR/100) ÷ 365; weekly interest is about $23.01, calculated before rounding. Changing the payment does not change that initial snapshot.
Minimum rule, wages and dates
The illustrative rule starts at the larger of $25 or 1% of opening balance plus posted interest. Both settings are editable assumptions, not a federal minimum or your issuer’s rule.
Optional hourly pay converts the weekly interest snapshot into work time. Choose gross or take-home pay consistently. Leaving it blank keeps all monetary results.
Month one is one calendar month after your as-of date. Dates stay anchored to its day: January 31 becomes February 28 or 29, then March 31. A payment that cannot reduce principal has no payoff date; a 1,200-month cutoff shows partial totals. Sources reviewed October 11, 2026.
Sources
Frequently asked questions
Does this reproduce my card statement?
No. Issuer formulas, daily balances, fees, purchases and grace periods can change the amount due.
Must I enter my pay?
No. Hourly pay is optional and affects only the work-time comparison.
Why is a payment non-amortizing?
It does not reduce principal under the model, usually because it is no larger than posted interest. A separate extra-payment scenario may still repay.
Is the suggested payment my required minimum?
No. It is the first posted interest plus one cent, evaluated through the same bounded schedule. It may still reach the 1,200-month limit.
Are the minimum-rule defaults official?
No. They are editable illustrative assumptions. Use your statement for the payment your issuer requires.