APR is the yearly interest rate a card issuer charges when you carry a balance
APR stands for Annual Percentage Rate. It is the percentage of your balance that the card issuer charges you in interest over one year. If your card has a 20% APR and you carry a $1,000 balance for a full year without making payments, you will owe roughly $200 in interest on top of the original $1,000.
The word "annual" is key: APR is always expressed as a yearly rate, even though interest compounds and is charged monthly. Your monthly interest charge is roughly one-twelfth of the APR. A 24% APR means about 2% interest per month, though the exact calculation depends on how your issuer compounds interest and which days of your billing cycle they count.
APR only matters if you carry a balance past your due date. If you pay your full statement balance by the due date every month, you pay zero interest regardless of the APR. The APR sits in the background until you stop paying in full.
Key Takeaways
- APR is the yearly interest rate charged on balances you do not pay in full; it is expressed as a percentage and varies by card and cardholder.
- Different APRs apply to different types of transactions: purchases, balance transfers, and cash advances often have separate rates.
- Introductory APR offers (0% for a set period) are temporary; the regular APR kicks in when the offer ends.
- Your actual APR depends partly on your creditworthiness; the same card may have different APRs for different people.
- Interest compounds monthly, so a high APR on a large balance grows quickly if you only make minimum payments.
How APR varies by transaction type on the same card
Most cards have at least two APRs: one for purchases and one for cash advances. A card might offer 18% APR on purchases but 25% APR on cash advances (withdrawals from an ATM). Balance transfer APR — the rate applied when you move a balance from another card — is often different again.
Cash advance APR is almost always higher than purchase APR, and interest on cash advances usually starts accruing immediately, with no grace period. A grace period is the window between your statement closing date and your due date during which no interest is charged on purchases if you pay in full. Cash advances skip this grace period entirely.
When you make a payment on a card with multiple balances, the issuer applies your payment to the lowest-APR balance first (by law in most states). This means if you have a 0% balance transfer and a 20% purchase balance, your payment goes to the 0% balance first, and the 20% balance keeps growing. Understanding this matters if you are juggling multiple rates on one card.
Introductory APR offers and when they end
Many cards advertise 0% APR for a set period — commonly 6 to 21 months — on purchases, balance transfers, or both. This is a temporary rate. When the introductory period ends, the regular APR takes over automatically.
The catch: if you still carry a balance when the intro period ends, interest charges jump to the full APR on the remaining balance. A $5,000 balance at 0% for 12 months becomes a $5,000 balance at 18% APR the moment month 13 begins. The issuer will notify you in writing before the intro period ends, but the responsibility to plan around it is yours.
Intro offers are most useful if you have a specific plan to pay off the balance before the period ends, or if you are moving a balance from a higher-APR card and the intro period gives you breathing room to pay it down faster.
Why your APR might differ from someone else's with the same card
Card issuers set a range for each card's APR — say, 18% to 28% — and assign you a specific rate within that range based on your credit score, payment history, and income. Someone with a 750 credit score might get 18% APR on a card while someone with a 650 score gets 26% on the same card.
Your APR can also change over time. If you miss payments or your credit score drops, the issuer may increase your APR (though they must give you advance notice). Conversely, if you maintain a good payment history, some issuers will lower your APR if you call and ask, though they are not required to.
The APR you see advertised is the issuer's "purchase APR" for a hypothetical applicant with good credit. The Schumer Box — the standardized disclosure table on a card's terms page — shows the APR range, not a single number.
How interest actually compounds on a monthly basis
APR is divided by 12 to get a monthly rate, but the calculation is not exact because months have different numbers of days. Most issuers use the Average Daily Balance method: they add up your balance for each day of the billing cycle, divide by the number of days, then multiply by the monthly interest rate.
If you have a $1,000 balance for 15 days and a $500 balance for 15 days in a 30-day month, your average daily balance is $750. At a 20% APR (roughly 1.67% per month), you owe about $12.50 in interest that month. The interest is added to your balance, and next month's interest is calculated on the new total — that is compounding.
This is why carrying a balance is expensive: interest charges grow on top of themselves. A $5,000 balance at 20% APR costs about $83 per month in interest alone if you make no payments. After six months of no payments, you owe roughly $5,500 in principal plus interest.
APR versus other card fees and charges
APR is separate from annual fees, late fees, and foreign transaction fees. A card might have a $95 annual fee and a 20% APR. You pay the annual fee whether you carry a balance or not. Interest charges only apply if you do carry a balance.
Late fees are charged when you miss a due date; they are a flat dollar amount (often $25 to $40) and are separate from APR. A late payment also triggers a penalty APR — a higher rate applied to your balance for six months or until you make six consecutive on-time payments. Penalty APR can be 29% or higher.
Some cards offer a 0% APR intro period but still charge an annual fee. The fee is worth paying only if you plan to use the card enough to earn rewards that exceed the fee, or if you are using the 0% period to pay down a large balance.
How to compare APR across different cards
APR alone does not tell you the full cost of a card. Two cards with the same 20% APR might have different annual fees, different grace periods, or different rewards structures. A card with a higher APR but strong cash-back rewards might be cheaper overall if you pay in full every month (because you never pay interest).
If you plan to carry a balance, focus on the APR first, then check for annual fees and the length of any grace period. A card with a lower APR and no annual fee is almost always cheaper than a card with a higher APR and a $95 fee, assuming you carry a balance.
If you are considering a balance transfer, compare the intro APR period length and any balance transfer fee (usually 3% to 5% of the amount transferred). A card offering 0% APR for 18 months with a 3% transfer fee might save you money compared to a card with 0% for 12 months and no fee, depending on your balance size and payoff timeline.
Frequently Asked Questions
Does APR apply if I pay my full balance every month?
No. If you pay your entire statement balance by the due date, you pay no interest regardless of the APR. The APR only applies to balances you carry past the due date. This is why paying in full is the most effective way to avoid interest charges.
Can a card issuer raise my APR without warning?
No, they must notify you in writing at least 45 days before increasing your APR. However, they can raise your rate after that notice period ends. Penalty APR (applied after a late payment) can take effect immediately, but you must still receive advance notice of the terms.
What is the difference between APR and interest rate?
APR and interest rate are often used interchangeably for credit cards. APR includes the interest rate plus any fees built into the yearly cost, though for most cards the APR is simply the interest rate expressed as a yearly percentage.
If I make a partial payment, which part of my balance does interest apply to?
Interest applies to the entire remaining balance. If you owe $2,000 and pay $500, interest is charged on the remaining $1,500, not just the unpaid portion. This is why even small payments reduce the total interest you pay over time.
Can I negotiate a lower APR with my card issuer?
You can ask, especially if you have a good payment history and a decent credit score. Some issuers will lower your APR if you call and request it, but they are not required to. The worst they can say is no. Switching to a card with a lower APR is often easier than negotiating.