Credit Card APR Calculator
APR sounds abstract — let's turn it into real numbers. See exactly what your interest rate means in daily, monthly, and annual costs.
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Leave at 0 to just see rate conversions
Daily Rate
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APR ÷ 365
Equivalent Monthly Rate
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Rate that compounds to APR over 12 months
What this means: For every $1,000 you carry on this card, you pay — in interest per month and — per year.
Understanding APR
APR stands for Annual Percentage Rate. But credit cards don't charge interest once a year — they calculate it daily.
Here's the breakdown:
- Daily Periodic Rate = APR ÷ 365
- Equivalent Monthly Rate = (1 + APR)1/12 − 1 — this is the rate that, when compounded monthly for 12 months, equals the APR. Note: many cards use the simple formula APR ÷ 12, but the equivalent rate is more precise.
- Average Daily Balance Method: The bank averages your balance across the billing cycle, then multiplies by the daily rate and number of days.
- Grace Period: Most cards waive interest if you pay your statement balance in full by the due date. Once you carry a balance, you lose the grace period.
The average credit card APR in the US as of 2025 is around 24.99%. Anything below 20% is considered good; above 30% is very high.