How is credit card interest calculated?

Credit card interest is calculated using your APR. Monthly interest = balance × (APR ÷ 12). Daily interest = balance × (APR ÷ 365). Interest compounds on unpaid balances.

Credit Card Interest Calculator

Estimate monthly and annual interest cost for a credit card balance.

This tool runs in your browser. None of your data is saved or sold.

Balance ($)

APR (%)

About This Calculator

This calculator converts your card's APR into the actual dollar cost of carrying a balance. It's most useful when you're deciding whether to pay off a card versus keeping money in savings — if your savings rate is lower than your card's daily interest rate, the math is clear.

Estimates only — not financial, tax, legal, or investment advice. Verify important results with a qualified professional before making decisions.

daily interest = balance × APR ÷ 365; monthly = balance × APR ÷ 12; annual = balance × APR