Glossary
APR (Annual Percentage Rate)
APR is the yearly interest rate charged on any balance you carry past your credit card statement due date, expressed as a single percentage so cards are comparable.
APR is quoted as an annual figure, but credit card issuers actually charge interest monthly — typically APR ÷ 12 applied to your average daily balance. A 36% APR therefore works out to roughly 3% per month on whatever you carry over.
APR only applies once you miss the interest-free grace period by not paying your statement balance in full. Pay in full every month and the APR never touches you, no matter how high it is — this is why the APR is usually the least important number for someone who always clears their balance, and the most important number for anyone who might carry a balance occasionally.
When comparing cards, check whether the advertised APR is a flat rate for everyone or a range ("24.99%–41.99% APR") that depends on your creditworthiness — the rate you are actually offered can land anywhere in that range.