Credit Card Interest Calculator
Estimate interest on revolving balances using APR (daily rate) + payments + fees.
Outstanding balance that will carry interest.
Many cards have 24%–48% APR depending on card type.
If you paid something during the period, enter it here.
Late fee / cash advance fee etc.
Most cards compute interest daily. This tool gives an estimate.
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Enter values to estimate interest cost.
Explanation
Credit cards typically charge interest when you carry a balance from one billing cycle to the next. Interest is usually calculated using a daily periodic rate (APR ÷ 365), applied to your balance each day. Paying more than the minimum reduces interest and helps you clear the balance faster.
Formula
Daily rate = APR / 365 Simple estimate: Interest ≈ Balance × (APR/365) × Days Daily compounding (approx): Balance_end ≈ (Balance - Payment + Fees) × (1 + APR/365)^Days Interest ≈ Balance_end - (Balance - Payment + Fees)
FAQs
Grace period?
Many cards waive interest if you pay the full statement balance by the due date. Cash advances usually don’t get a grace period.
Minimum payment effect?
Paying minimum keeps you in debt longer and you pay much more interest overall.
Cash advances?
They often start interest immediately and have extra fees. Always check your card terms.
Compounding frequency?
Many issuers compute interest daily based on your daily balance (estimated here).
Fees?
Fees can increase your outstanding balance, which can increase interest too.