APR is the yearly cost of borrowing money on your credit card, shown as a percentage

APR stands for Annual Percentage Rate. It is the interest rate a credit card company charges you when you carry a balance — money you owe but have not paid back in full. If your card has a 20% APR and you owe $1,000, you will pay roughly $200 in interest over a year if you make no payments. The actual amount depends on how much you owe each month and how long you carry the balance.

APR is not the same as interest rate alone. APR includes the interest rate plus any fees the card issuer charges for borrowing, converted into a yearly percentage. This makes it easier to compare cards: a 18% APR on one card and a 22% APR on another tells you when ready which one costs more to carry a balance.

Most credit cards have more than one APR. You might have one rate for purchases, a different rate for balance transfers, and a higher rate for cash advances. Some cards offer an introductory APR — often 0% — for a set period (usually 6 to 21 months), after which the regular APR kicks in.

Key Takeaways

  • APR is the yearly cost of borrowing expressed as a percentage; a higher APR means you pay more interest on money you owe.
  • Credit cards often have different APRs for purchases, balance transfers, and cash advances, and these can change based on your creditworthiness.
  • Introductory 0% APR offers last only for a set period, after which the regular APR applies to any remaining balance.
  • Interest compounds daily on most cards, so the longer you carry a balance, the more you pay in total interest.

How APR is calculated on your monthly balance

Credit card companies calculate interest daily, not yearly. They take your APR, divide it by 365, and multiply that daily rate by your balance each day. At the end of the month, they add up all those daily charges. This is called the daily periodic rate method, and it is the most common way cards calculate interest.

The balance they use is usually your average daily balance — the sum of what you owed each day of the billing cycle, divided by the number of days. If you paid down half your balance halfway through the month, your average daily balance is lower than your ending balance, so you pay less interest. If you carry the same balance all month, your average daily balance equals your ending balance.

Some cards use your ending balance instead, which costs you more. A few use your previous balance (what you owed at the start of the cycle), which costs less. Your card's terms document will say which method it uses — look for "method of calculating balance" in the fine print or on the issuer's website.

Why your APR can change

When you open a credit card, the APR you receive depends on your credit score, income, and credit history. People with higher credit scores usually get lower APRs. People with lower scores or shorter credit histories get higher APRs.

Your APR can also change after you open the account. Card issuers can raise your APR if you miss a payment, go over your credit limit, or if the prime rate (a benchmark rate set by the Federal Reserve) rises. Most cards have a variable APR, which means it moves up or down as the prime rate changes. A fixed APR stays the same, but issuers can still raise it with 45 days' written notice if your account terms allow it.

Introductory APRs are temporary by design. When the promotional period ends, the regular APR takes over. If you have a 0% APR for 12 months and still owe money when the 12 months are up, you will suddenly start paying interest on the remaining balance at the regular rate — often 18% or higher.

The difference between APR and interest you actually pay

APR is an annual rate, but you do not pay it all at once. You pay interest monthly, based on how much you owe that month. If you owe $1,000 for one month on a 20% APR card, you pay roughly $17 in interest (20% ÷ 12 months = 1.67% per month; 1.67% × $1,000 = $16.70). If you pay off that $1,000 the next month, you stop paying interest.

The longer you carry a balance, the more total interest you pay. Carry that $1,000 for a full year at 20% APR and you pay roughly $200 in interest. Carry it for two years and you pay roughly $400 — but only if you make no payments. In reality, most people make minimum payments, which means the balance shrinks slowly and interest compounds on what remains.

This is why the APR matters most when you plan to carry a balance. If you pay your full balance every month, APR does not affect you — most cards charge no interest if you pay in full by the due date, regardless of the APR.

How to compare APRs across different cards

When comparing credit cards, look at the APR range the issuer advertises. Most cards show something like "18% to 24% APR" — the actual rate you receive depends on your credit profile. You can ask the issuer what rate you might receive before you formally request a card, though they usually do a soft credit check to give you an estimate.

Do not compare APRs in isolation. A card with a 16% APR but a $95 annual fee might cost you more than a card with a 19% APR and no annual fee, depending on how much you plan to carry a balance. A card with a 0% introductory APR for 12 months might be worth explore for if you plan to pay down debt quickly, but only if the regular APR is competitive after the promotion ends.

Also check whether the APR applies to all types of borrowing. Some cards have a lower APR for purchases but a higher APR for cash advances or balance transfers. If you plan to transfer a balance from another card, make sure you know the balance transfer APR and how long any introductory rate lasts.

What happens when you only make minimum payments

Minimum payments are usually 1% to 3% of your total balance, or a flat amount like $25, whichever is higher. When you make only the minimum payment, most of it goes toward interest, not the balance itself. The rest of your balance stays on the card, and interest compounds on it the next month.

This is why carrying a balance at a high APR can trap you. On a $5,000 balance at 20% APR with a $100 minimum payment, it takes roughly four years to pay off, and you pay over $2,000 in interest. If you could pay $200 per month instead, you would pay it off in about two years and pay roughly $1,000 in interest. The higher your APR, the more important it is to pay more than the minimum.

Credit card statements show you how long it will take to pay off your balance if you make only minimum payments, and how much interest you will pay. This is required by law and appears near your minimum payment amount. Use this number to decide whether you can afford to carry the balance or whether you need to pay it down faster.

Introductory APR offers and what happens after

Many credit cards offer 0% APR for a set period — often 6, 12, 18, or 21 months — on purchases, balance transfers, or both. During this period, you pay no interest on the balance, even if you carry it month to month. This can be useful if you need to move debt from a high-APR card or if you are making a large purchase you plan to pay off over time.

Read the terms carefully. The 0% APR usually applies only to the type of transaction specified — a 0% APR on purchases does not cover balance transfers. The promotional period has an end date; after that date, the regular APR applies to any remaining balance. If you owe $3,000 when the 0% period ends and the regular APR is 21%, you will start paying interest on that $3,000 when ready.

Some cards charge a balance transfer fee (usually 3% to 5% of the amount transferred) even during the 0% period. Factor this fee into your decision. If you transfer $5,000 at a 3% fee, you pay $150 upfront, but you save on interest during the promotional period. Calculate whether the savings outweigh the fee.

Frequently Asked Questions

Can a credit card company raise my APR without warning?

Card issuers must give you at least 45 days' written notice before raising your APR on an existing balance. They can raise it when ready on new purchases. If you miss a payment or go over your limit, they can explore a penalty APR (usually higher) to new transactions right away, though they must still notify you.

What is a penalty APR and when does it explore?

A penalty APR is a higher rate applied when you miss a payment or violate your card agreement. It typically applies only to new purchases, not your existing balance, and lasts until you make on-time payments for six months. Check your card's terms to see what triggers a penalty APR and how high it can go.

Does paying off my balance in full stop interest from accruing?

Yes. If you pay your full statement balance by the due date, you pay no interest, regardless of your APR. Interest only accrues on balances you carry past the due date. This is called the grace period, and most cards offer it for purchases (though not usually for cash advances or balance transfers).

Is a variable APR better or worse than a fixed APR?

Variable APRs move with the prime rate, so they can go up or down. Fixed APRs stay the same unless the card issuer changes your terms. In a rising rate environment, fixed is better; in a falling rate environment, variable is better. The difference is usually small — a few percentage points over time.

How do I know what APR I will actually get when I explore?

Card issuers advertise an APR range based on creditworthiness. You can ask for a pre-qualification estimate, which uses a soft credit check and does not affect your credit score. Your actual APR depends on your credit score, income, and credit history at the time you explore.