Credit card loans cost you interest, and the rate depends on your credit score, the card issuer, and the type of balance

When you carry a balance on a credit card — meaning you don't pay off what you owe in full each month — the card issuer charges you interest. This interest is expressed as an Annual Percentage Rate, or APR. The APR is the yearly cost of borrowing, shown as a percentage of what you owe.

If you have a $1,000 balance and your card has a 20% APR, you will owe roughly $200 in interest over a year if you make no payments. In practice, most people make monthly payments, so the actual interest is lower — but it still adds up fast. Credit card APRs typically range from 15% to 29%, though some cards offer rates as low as 12% or as high as 36%, depending on your credit history and the issuer.

The card issuer sets your APR based on your credit score at the time you open the account. If your score improves later, the issuer is not required to lower your rate — you would need to ask for a rate reduction, and they can refuse. If your score drops or you miss a payment, many issuers can raise your APR to a penalty rate, which can be 29% or higher.

Key Takeaways

  • Credit card APRs range from roughly 12% to 36% and are set based on your credit score when you open the account.
  • Interest is calculated daily on your outstanding balance, so carrying a balance costs you money every single day until you pay it off.
  • Late fees, annual fees, and balance transfer fees are separate charges on top of interest and can add hundreds of dollars per year.
  • A 0% introductory APR offer typically lasts 6 to 21 months, after which the regular APR kicks in — read the fine print to know when.
  • Paying only the minimum payment means most of your payment goes to interest, not to reducing what you owe.

How interest is calculated and when it starts

Credit card companies calculate interest daily. They take your balance at the end of each day, divide your APR by 365, and multiply by that day's balance. This happens every single day, and the daily interest charges are added to your balance. At the end of your billing cycle, you see the total interest owed.

Interest starts accruing immediately when you carry a balance — there is no grace period once you have unpaid debt. However, if you pay your full statement balance by the due date each month, you pay no interest at all. This is why paying in full is the only way to avoid interest charges entirely.

If you make a purchase and then make a payment before the next statement closes, the interest calculation gets more complex. Most issuers use the "average daily balance" method, which factors in both the purchase and the payment across the billing cycle. The exact calculation varies by issuer, so check your card's terms to understand how your interest is computed.

Other charges that add to what you owe

Late fees are charged when you miss a payment deadline. Federal law caps late fees at $29 for a first violation and $40 for subsequent violations within six months, though issuers often charge less. A single late payment also triggers a penalty APR, which can jump your rate to 29% or higher and may apply to new purchases as well as your existing balance.

Annual fees are charged once per year just for holding the card, regardless of whether you use it. Annual fees range from $0 to over $500 on premium cards. Many basic cards have no annual fee, but cards with rewards programs or travel benefits often charge $95 to $450 per year.

Balance transfer fees are charged when you move a balance from one card to another. These typically run 3% to 5% of the amount transferred. If you transfer $5,000 at a 3% fee, you pay $150 upfront. Balance transfers often come with a 0% introductory APR, but the fee is charged immediately.

Cash advance fees are charged when you withdraw cash using your credit card at an ATM. These fees are usually 3% to 5% of the amount withdrawn, with a minimum of $3 to $10. Cash advances also carry a higher APR than purchases — often 2% to 3% higher — and interest starts accruing immediately with no grace period.

How your credit score affects the rate you pay

Credit card issuers use your credit score to decide what APR to offer you. A score of 750 or higher typically qualifies for rates in the 12% to 18% range. A score between 650 and 749 usually means rates of 18% to 24%. A score below 650 often results in rates of 24% to 29% or higher.

Your credit score is based on payment history (35%), amounts owed (30%), length of credit history (15%), credit mix (10%), and new credit inquiries (10%). A single late payment can drop your score by 100 points or more, which can immediately raise your APR if the issuer reviews your account. Paying on time, keeping balances low relative to your credit limits, and avoiding new credit inquiries all help keep your score — and your APR — lower.

Introductory 0% APR offers and what happens after

Many credit cards offer a 0% introductory APR for a set period — typically 6 to 21 months — on purchases, balance transfers, or both. During this period, you pay no interest on the may have access to balance. However, the offer is temporary. Once the introductory period ends, the regular APR kicks in, and interest accrues on any remaining balance at the full rate.

The length of the 0% period depends on the card and the offer. Balance transfer 0% offers tend to be shorter (6 to 12 months) than purchase 0% offers (12 to 21 months). Read the card's terms carefully to know the exact end date. If you still owe money when the period ends, you will suddenly start paying interest at the regular APR, which can be 18% to 29%.

A 0% offer can be useful if you have a plan to pay off the balance before the period ends. If you do not pay it off in time, you will owe interest on the full remaining balance retroactively — meaning interest accrues as if the 0% period never happened. Some cards offer this retroactive interest; others do not. Check the terms to know which applies to your card.

Minimum payments and how long debt takes to repay

Your credit card statement shows a minimum payment — usually 1% to 3% of your total balance, or a fixed amount like $25, whichever is higher. Paying only the minimum keeps you out of default, but it means most of your payment goes to interest, not to reducing what you owe.

If you have a $5,000 balance at 20% APR and pay only the $25 minimum each month, it will take you roughly 30 years to pay off the debt, and you will pay over $8,000 in interest alone. If you pay $200 per month instead, you will pay off the same balance in about 2.5 years and pay roughly $1,200 in interest. The difference between minimum and aggressive repayment is enormous.

To see how long your specific debt will take to repay, use a credit card payoff calculator and enter your balance, APR, and the monthly payment you plan to make. This gives you a realistic picture of the cost and timeline before you commit to a payment plan.

Comparing costs across different cards and offers

Not all credit cards cost the same. A card with a 15% APR and no annual fee is cheaper to carry a balance on than a card with a 24% APR and a $95 annual fee. However, the card with the higher APR might offer better rewards on purchases, which could offset the higher interest cost if you pay in full each month.

When comparing cards, look at the full picture: the APR, any annual fee, the length of any 0% introductory offer, and the rewards or benefits you actually use. If you plan to carry a balance, prioritize a low APR and no annual fee. If you pay in full each month, the APR matters less, and rewards or benefits become more important.

Balance transfer cards can save you money if you have existing high-interest debt. A card offering 0% APR on balance transfers for 12 months plus a 3% transfer fee might cost you $150 to move a $5,000 balance, but you save $1,000 in interest over that year compared to leaving the balance on a 20% APR card. The math changes depending on your balance and the offers available to you.

Frequently Asked Questions

What is the average credit card APR right now?

The average APR varies by week and by issuer, but as of 2024 it typically ranges from 18% to 22% for cards offered to people with good credit. Cards for people with fair or poor credit often carry rates of 24% to 29%. Check the specific card's terms to see what rate you would receive, as rates are set individually based on your credit score.

Can a credit card company raise my APR without warning?

Yes, but they must give you 45 days' notice before the increase takes effect. If you miss a payment, they can apply a penalty APR immediately. You can reject the rate increase and close the card, though this affects your credit score. Paying on time is the best way to avoid rate increases.

Does paying interest on a credit card build my credit score?

No. Paying interest does not help your credit score — it just costs you money. What helps your score is paying on time and keeping your balance low relative to your credit limit. You can build credit without paying any interest by paying your full balance each month.

What happens if I only pay the interest and not the principal?

If you pay only the interest charges and not the principal (the original amount you borrowed), your balance never decreases. You will owe interest forever. You must pay more than the interest charges to reduce what you owe. Even paying slightly above the minimum helps reduce the principal and saves you money over time.

Is there a way to lower my credit card APR?

You can call your card issuer and ask for a lower rate, especially if your credit score has improved since you opened the account or if you have been a good customer with on-time payments. Some issuers will negotiate; others will not. There is no harm in asking, but they can refuse. Switching to a card with a lower APR is another option if you may have access to.