Credit Card Interest Calculator

Card interest is high and it compounds. Across all credit card accounts at commercial banks the average rate was 20.94%, and across accounts actually being charged interest it was 22.15% (Federal Reserve G.19, May 2026). Store cards and cards sold to thin credit files are often higher again.

Interest is normally worked out on the balance each day, so a payment made earlier in the month saves slightly more than the same payment made later. Pay the statement in full within the grace period and a normal purchase card charges nothing at all; carry any balance and the grace period typically disappears until it is cleared.

Minimum payments are commonly set around one to three percent of the balance plus interest and fees, which is why the schedule below stretches so far when you pay only the minimum.