Your card’s APR is converted into a daily rate, and interest is calculated on your balance each day. Divide the APR by 365 to get the daily periodic rate (some issuers use 360). That interest is added to your balance and then interest can accrue on it too, which is how debt grows quickly.
For a simple estimate, a $1,000 balance at a 24% APR costs roughly $20 in interest per month (24% divided by 12 months is 2%). The exact amount depends on your daily balances and billing cycle length.
Types of Credit Card APR
- Purchase APR: The rate on everyday purchases you don’t pay off in full.
- Balance transfer APR: The rate on debt moved from another card. Some cards offer an introductory 0% rate. See balance transfer credit cards.
- Cash advance APR: Usually higher than the purchase APR, and interest typically starts immediately with no grace period.
- Introductory APR: A low or 0% rate for a limited time, after which the regular APR applies.
- Penalty APR: A higher rate that some issuers may apply if you pay late. Check your card agreement for the terms.
Fixed vs. Variable APR
Most credit cards have a variable APR, which is tied to a benchmark such as the prime rate. When the prime rate moves, your APR can move with it. Card rates have been above 20% on average in recent years, and the Federal Reserve publishes data on current averages.
What Is a Grace Period?
A grace period is the time between the end of your billing cycle and your payment due date. Federal law requires issuers to send your statement at least 21 days before the due date. If you pay your full statement balance by then, you generally won’t be charged interest on new purchases. If you carry a balance from month to month, you usually lose the grace period, and interest starts accruing on new purchases right away.
APR vs. Interest Rate
For credit cards, the two terms are used almost interchangeably. APR can include certain fees in other types of loans, such as mortgages, but on credit cards it mostly reflects the interest rate. Annual fees and other charges are separate. See credit card fees explained.
What Determines Your APR?
- Your credit score: Better credit generally means a lower rate. See what is a good credit score.
- The type of card: Rewards and premium cards often have higher APRs than basic cards.
- The issuer: Credit unions often offer lower rates than large banks.
- Economic conditions: Because most APRs are variable, they follow broader interest rate changes.
How to Avoid Paying Credit Card Interest
- Pay your statement balance in full every month.
- Use autopay so you never miss a due date.
- Avoid cash advances, which start accruing interest immediately.
- Use a 0% intro APR offer carefully and have a plan to pay off the balance before it ends.
- Ask your issuer for a lower rate. It doesn’t always work, but it costs nothing to ask, especially if you have a strong payment history.
- If you already have a balance, read our guide on how to pay off credit card debt.
Frequently Asked Questions
What is a good APR for a credit card?
It depends on your credit and the type of card. A lower APR is always better, but if you pay in full each month, APR matters less than fees and rewards.
Do I pay APR if I pay my balance in full?
Generally not on purchases, as long as you pay the full statement balance by the due date.
Can my APR change?
Yes. Variable APRs can change with the market, and promotional rates end after a set period. Issuers must give notice before raising rates on existing balances in most situations.
Is a 0% APR really free?
The interest is 0% during the promotional window, but a balance transfer fee may apply, and any remaining balance is charged the regular APR when the offer ends.
Disclosure: This article is for educational purposes only and is not financial advice. Some links on this site may earn us a commission at no cost to you. Read our affiliate disclosure and full disclaimer. Card terms change often, so confirm current rates and fees with the issuer.