How Credit Card APR & Interest Work
APR stands for Annual Percentage Rate — the yearly cost of borrowing on a credit card, expressed as a percentage. Understanding APR is one of the most important things you can learn about credit cards, because it determines how much carrying a balance actually costs you.
A credit card's annual percentage rate, or APR, represents the yearly cost of borrowing money expressed as a percentage. When you carry a balance on your credit card, interest accrues based on your APR and outstanding balance. Understanding how this interest is calculated and the conditions under which it applies can help you make informed decisions about credit card use. This guide provides general educational information about these concepts and does not constitute financial advice. Consult a financial professional for guidance specific to your situation.
What APR means
A credit card's APR is the yearly interest rate you're charged on balances you don't pay off. The CFPB notes that for credit cards, the APR and the interest rate are effectively the same thing. Most cards have a variable APR tied to an index (like the prime rate), so it can change over time. A single card can have several APRs — for purchases, balance transfers, and cash advances — and these are often different.
How interest is calculated
Interest is typically calculated using your average daily balance and a daily periodic rate (your APR divided by the days in the year), then applied each billing cycle. The key consequence: the longer you carry a balance, the more interest accrues, and unpaid interest can compound.
The grace period — how to pay no interest
Most cards offer a grace period on purchases: if you pay your statement balance in full by the due date, you generally pay no interest on new purchases. Carrying a balance can cause you to lose that grace period until you pay in full again. Paying in full each month is the simplest way to avoid interest entirely.
Cash advances and other rates
Cash advances usually have a higher APR and often start accruing interest immediately, with no grace period — so they're an expensive way to access cash. Always read your card's terms (the "Schumer box") to see each APR and when interest applies.
Sources: CFPB — What does APR mean?; CFPB — Credit Cards. Credit-card information follows the U.S. Consumer Financial Protection Bureau (CFPB) and the Federal Reserve; always confirm current rates, fees, and terms with the issuer before applying.
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Compare card offers / get matched →Frequently asked questions
What does APR mean on a credit card?
APR is the Annual Percentage Rate — the yearly cost of borrowing on the card. For credit cards, the CFPB explains that the APR is essentially the interest rate. If you pay your statement balance in full each month, you generally won't be charged that interest on purchases.
How can I avoid paying credit card interest?
Pay your full statement balance by the due date every month. Doing so preserves your grace period on purchases, so you're not charged interest on them. Cash advances are an exception — they often accrue interest right away.