Your card's interest rate is the annual percentage rate (APR) printed on your disclosure documents, and you calculate what you actually pay by multiplying your balance by that rate and dividing by 12

The interest rate on your credit card is stated as an annual percentage rate (APR). This is the percentage of your balance that the card issuer charges you per year. If your card has a 20% APR and you carry a $1,000 balance for a full year without paying it down, you will owe $200 in interest charges.

The actual math works like this: take your current balance, multiply it by your APR as a decimal, then divide by 12 to get the monthly interest charge. A $1,000 balance at 20% APR costs you about $16.67 per month in interest (1,000 × 0.20 ÷ 12 = 16.67). Most cards calculate interest daily instead of monthly, which means the exact amount depends on how many days are in your billing cycle and when you made purchases, but this formula gives you the right ballpark.

Key Takeaways

  • Your card's APR is listed on your Schumer Box (the disclosure table) and in your cardholder agreement, usually as a range like 18.99% to 24.99%.
  • The actual rate you receive depends on your creditworthiness at the time you open the account, and it can change if the card issuer raises rates or if you miss a payment.
  • Interest only accrues on balances you carry from one billing cycle to the next; paying your full statement balance by the due date means you pay zero interest.
  • Different purchases on the same card can have different APRs — balance transfers and cash advances often carry higher rates than regular purchases.
  • You can find your exact current APR in your online account, on your monthly statement, or by calling the customer service number on the back of your card.

Where to find your card's APR

Your card issuer must disclose the APR in two places. The first is the Schumer Box, a standardized table that appears in the offer materials before you open the account. This table shows the APR range — for example, 18.99% to 24.99% — and tells you that the actual rate you receive depends on your credit profile.

The second place is your cardholder agreement, the full terms document you receive after you open the account. This agreement lists your exact APR, not a range. You can also find your current APR by logging into your online account, checking your most recent statement, or calling the customer service number on the back of your card.

If you have an introductory 0% APR offer, that rate applies only to the purchase type specified in the offer — usually purchases, sometimes balance transfers. Once the promotional period ends, the regular APR kicks in. The end date of the promotional period is stated in your cardholder agreement and usually appears on your statement as well.

Why your APR might be different from the advertised range

Credit card companies advertise a range because they assign different rates to different people based on credit score, income, and payment history. If you have excellent credit, you might receive the lower end of the range. If your credit is fair or you have recent late payments, you might receive the higher end.

Your APR can also change after you open the account. Most cards have a variable APR, which means the rate moves up or down based on changes to the prime rate set by the Federal Reserve. When the Fed raises rates, your APR typically rises within one to three billing cycles. Card issuers must give you at least 21 days' notice before increasing your APR, and they must send the notice to the address on file.

A missed payment can also trigger a penalty APR, a higher rate that applies after you miss a payment by 60 days or more. Penalty rates can be several percentage points higher than your regular APR. You can lose the penalty rate if you make on-time payments for six months in a row, though the issuer is not required to lower it.

How different transactions on the same card can have different rates

A single card can carry multiple APRs depending on what you use it for. A purchase APR applies to regular purchases. A balance transfer APR applies if you transfer a balance from another card. A cash advance APR applies if you withdraw cash using the card at an ATM or through a cash advance check.

Balance transfer and cash advance APRs are almost always higher than the purchase APR. A card might offer 18% for purchases but 24% for balance transfers and 28% for cash advances. Interest on cash advances also starts accruing immediately — there is no grace period — so you begin paying interest the day you withdraw the cash.

When you make a payment, the card issuer applies it to the lowest-APR balance first (this is required by law). So if you have a $2,000 balance transfer at 24% and a $1,000 purchase balance at 18%, a $500 payment goes entirely to the purchase balance. This means your higher-rate balance shrinks more slowly.

The difference between APR and the interest you actually pay

APR is an annual rate, but you do not pay it all at once. The interest you actually owe depends on how long you carry the balance. If you carry a $1,000 balance at 20% APR for only three months before paying it off, you pay roughly $50 in interest (1,000 × 0.20 × 3/12 = 50), not the full $200.

The way interest compounds also matters. Most cards use average daily balance to calculate interest. This means the issuer adds up your balance at the end of each day in the billing cycle, divides by the number of days, and applies interest to that average. If you make a large purchase late in the cycle, it has less time to accrue interest that month.

If you pay your full statement balance by the due date, you pay zero interest, even if your APR is 25%. The grace period (usually 21 to 25 days from the statement closing date to the due date) applies only if you paid the previous statement in full. If you carry any balance, the grace period does not apply to new purchases, and interest starts accruing immediately.

How to compare APRs across different cards

When you are comparing cards, look at the APR range in the Schumer Box, but also consider what you plan to use the card for. If you intend to pay off your balance each month, the APR does not matter — you will pay no interest. If you plan to carry a balance, a card with a 1% or 2% lower APR will save you real money over time.

Also check whether the card offers an introductory 0% APR period. A card with a 22% regular APR but a 0% APR for 12 months on purchases can be a better choice than a card with an 18% APR if you need time to pay down a balance. Just make sure you know the exact end date of the promotional period and have a plan to pay the balance before the regular APR kicks in.

Do not assume your APR will stay the same. If the card has a variable rate, your APR will rise when the Fed raises rates. If you miss a payment, you could face a penalty APR. Build in a buffer when comparing cards — choose one with a lower APR than you think you need, so you have room if circumstances change.

What happens if you do not pay attention to your APR

Ignoring your APR and carrying a balance month after month is one of the most expensive mistakes you can make with a credit card. A $5,000 balance at 22% APR costs you about $91 per month in interest alone. If you make only minimum payments (usually 1% to 3% of the balance), most of your payment goes to interest, and the balance shrinks very slowly.

Using a balance transfer card with a 0% introductory APR can break this cycle, but only if you have a plan. Transfer the balance, commit to paying it down during the 0% period, and set a reminder for one month before the promotional period ends. If you still have a balance when the regular APR kicks in, you will be back to paying high interest.

The best way to avoid paying interest altogether is to treat your credit card like a debit card: spend only what you can pay off in full each month. If you cannot do that, focus on paying down the balance as fast as possible, starting with the highest-APR balances first.

Frequently Asked Questions

Can my APR change without notice?

No. Card issuers must send you written notice at least 21 days before increasing your APR. The notice goes to the address on file. If you have a variable APR, the rate can change when the prime rate changes, but the issuer still must notify you. You have the right to reject a rate increase by closing the account, though you will still owe the balance at the old rate.

What is the difference between a fixed APR and a variable APR?

A fixed APR does not change based on market conditions, though the issuer can still raise it with 21 days' notice if you miss a payment. A variable APR moves up and down with the prime rate. Most credit cards have variable APRs. Over time, variable rates tend to be cheaper when interest rates are falling and more expensive when they are rising.

If I have a 0% APR offer, do I pay interest on new purchases?

It depends on the offer. Some 0% offers apply only to balance transfers or only to purchases. Check your cardholder agreement to see which transactions are covered. If the offer covers purchases and you transfer a balance, the balance transfer might be at the regular APR while new purchases are at 0%. Once the promotional period ends, all balances revert to the regular APR.

Does paying more than the minimum payment lower my APR?

No. Your APR is set by the card issuer and does not change based on how much you pay. However, paying more than the minimum does lower the balance that interest accrues on, so you pay less total interest. Paying the full statement balance by the due date means you pay zero interest, regardless of your APR.

How do I know if my APR is competitive?

APRs vary widely based on credit score and market conditions. Cards for people with excellent credit (750+) often have APRs in the 16% to 20% range. Cards for people with fair credit (650–700) often have APRs in the 22% to 28% range. If your APR is significantly higher than these ranges, you may be able to find a better card once your credit improves, or you could contact your issuer to ask about a rate reduction.