How Is Credit Card Interest Calculated?
Credit card interest is the cost of borrowing money when you carry a balance past your grace period . Most issuers calculate it daily using your Annual Percentage Rate (APR) and your average daily balance. Understanding the exact steps helps you estimate charges, avoid surprises, and pay less over time. Steps Easy One-by-One Line Version Find your APR on the statement. Divide the APR by 365 to get the daily rate. Add up your balance for every day in the billing cycle. Divide that total by the number of days to get the average daily balance. Multiply average daily balance × daily rate × number of days. That final number is your interest charge. Complete Detailed Version Most U.S. credit card issuers use the average daily balance method . Here is the full process: Find your APR and convert it to a daily periodic rate Look on your statement or card agreement for the purchase APR (example: 22%). Divide by 365 (most issuers use 365; a few use 360 — check your terms): Daily pe...