How to Calculate APR on a Credit Card (2026)

Banks are notorious for making numbers complicated. Even something as seemingly simple as your credit card’s annual percentage rate (APR) becomes complex when trying to calculate how banks get that number. But not to fear — learning how to calculate APR on a credit card is possible, and we’ll show you how.

As a responsible consumer, you’re rightfully concerned as to how this perplexing number determines what you’re paying in interest charges. We’ve broken it all down for you as simply as possible and will show you:

1. Three simple steps for calculating your APR
2. How to pay no interest at all with a balance transfer
3. The best balance transfer cards available today

We’ll take you through step by step and explain the hows and whys of each. Let’s get started with calculating your APR.

It’s actually quite easy once you know the equation, which we’ll explain here.

1. Find Your Average Daily Periodic Rate

Your Average Daily Periodic Rate can be found at the bottom of your monthly statement. We’ll call it ADPR. This number will be very low and may not seem like much, but this is what you are being charged in interest on average daily. We’ll touch more on this in step 2, but for this calculation, we’ll assume it’s .04654.

2. Multiply ADPR By 365

Take the ADPR (.04654) and multiply it by 365, the number of days in a year. You use the number of days in a year because your interest compounds daily. Your ADPR represents what you are charged each day and is determined by your outstanding balance. Banks use the average balance over the entire billing cycle.

(.04654)(365) = 16.987

Note: Some credit card issuers use 360 instead of 365, according to the CFPB.

3. View Your APR

Round that number up to get 16.99% — your APR. The calculation is:

(ADPR)(365) = APR

If you’ve done the math and aren’t happy with what you see, there’s a way to stop paying interest for a while. It’s called a 0-percent intro APR, and some cards offer them for up to 18 months.

This works by applying for a new card and transferring your current balance to the new card. You’ll receive up to 18 months of an interest-free balance AND most cards even offer 0 percent interest on purchases. This means everything charged to the new card will also be interest free for a while, depending on your agreement.

Our experts are always looking for the best balance transfer cards, as they’re such a popular option among consumers today who are sick of paying sky-high interest rates. Granted, many factors determine the interest you’re being charged, but if you have good credit, you’ll likely qualify for one of these cards.

Below are a few of our experts’ top picks, but to see the full list, visit our balance transfer review page.

BankAmericard® credit card

CardRates Expert Rating

BankAmericard® credit card

4.6/5.0

About this rating

Our experts rate credit card offers based on factors like rewards, APRs, signup bonuses, fees, and approval rates, with a focus on benefits that provide the best value. We also consider cardholder needs such as credit-building potential, issuer reputation, and customer service. Our ratings are unbiased, updated regularly, and not influenced by issuers.

See Our Review»

Ashley Fricker Senior Editor

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★★★★★ 4.6/5.0

at Bank Of America'ssecure website

Our Review »

• New! 0% Intro APR for 21 billing cycles for purchases, and for any balance transfers made in the first 60 days. After the Intro APR offer ends, a Variable APR that’s currently 14.99% - 25.99% will apply. A 5% fee applies to all balance transfers. Balance transfers may not be used to pay any account provided by Bank of America.
• No annual fee.
• No penalty APR. Paying late won't automatically raise your interest rate (APR). Other account pricing and terms apply.
• This offer may not be available elsewhere if you leave this page. You can take advantage of this offer when you apply now.

Show MoreShow Less See application, terms and details »

Intro (Purchases) 0% Intro APR for 21 billing cycles for purchases

Intro (Transfers) 0% Intro APR for 21 billing cycles for any balance transfers made in the first 60 days (Balance Transfer Fee 5% of the amount of each transaction)

Regular APR 14.99% - 25.99% Variable APR on purchases and balance transfers

Annual Fee $0

Credit Needed Excellent/Good

Citi® Diamond Preferred® Card

CardRates Expert Rating

Citi® Diamond Preferred® Card

4.5/5.0

About this rating

Our experts rate credit card offers based on factors like rewards, APRs, signup bonuses, fees, and approval rates, with a focus on benefits that provide the best value. We also consider cardholder needs such as credit-building potential, issuer reputation, and customer service. Our ratings are unbiased, updated regularly, and not influenced by issuers.

See Our Review»

Ashley Fricker Senior Editor

Close

★★★★★ 4.5/5.0

at Citi'ssecure website

Our Review »

• 0% Intro APR on balance transfers for 21 months and on purchases for 12 months from date of account opening. After that the variable APR will be 16.49% - 27.24%, based on your creditworthiness. Balance transfers must be completed within 4 months of account opening.
• There is an intro balance transfer fee of 3% of each transfer (minimum $5) completed within the first 4 months of account opening. After that, your fee will be 5% of each transfer (minimum $5).
• No Annual Fee - our low intro rates and all the benefits don't come with a yearly charge.
• Buy now and pay later. Split your payment for eligible purchases of $75 or more into a fixed payment with Citi® Flex Pay.
• Get free access to your FICO® Score online.

Show MoreShow Less See application, terms and details »

Intro (Purchases) 0% 12 months on Purchases

Intro (Transfers) 0% 21 months on Balance Transfers

Regular APR 16.49% - 27.24% (Variable)

Annual Fee $0

Credit Needed Good/Excellent

See Rates & Fees »

BankAmericard® credit card for Students

CardRates Expert Rating

BankAmericard® credit card for Students

4.5/5.0

About this rating

Our experts rate credit card offers based on factors like rewards, APRs, signup bonuses, fees, and approval rates, with a focus on benefits that provide the best value. We also consider cardholder needs such as credit-building potential, issuer reputation, and customer service. Our ratings are unbiased, updated regularly, and not influenced by issuers.

See Our Review»

Ashley Fricker Senior Editor

Close

★★★★★ 4.5/5.0

at Bank Of America'ssecure website

Our Review »

• New! 0% Intro APR for 21 billing cycles for purchases, and for any balance transfers made in the first 60 days. After the Intro APR offer ends, a Variable APR that’s currently 14.99% - 25.99% will apply. A 5% fee applies to all balance transfers. Balance transfers may not be used to pay any account provided by Bank of America.
• No annual fee.
• No penalty APR. Paying late won't automatically raise your interest rate (APR). Other account pricing and terms apply.
• When handled responsibly, a credit card can help you build your credit history, which could be helpful when looking for an apartment, a car loan, and even a job.
• This offer may not be available elsewhere if you leave this page. You can take advantage of this offer when you apply now.

Show MoreShow Less See application, terms and details »

Intro (Purchases) 0% Intro APR for 21 billing cycles for purchases

Intro (Transfers) 0% Intro APR for 21 billing cycles for any balance transfers made in the first 60 days (Balance Transfer Fee 5% of the amount of each transaction)

Regular APR 14.99% - 25.99% Variable APR on purchases and balance transfers

Annual Fee $0

Credit Needed Excellent/Good

By understanding your APR, you’ll be able to comprehend how interest is calculated and tacked on to your monthly bill. This should prompt you to pay your balance off every month because those interest fees can have a considerable impact on budgets. But if you carry a balance, hopefully by now you’ve decided you’re not going to settle for paying high interest (or any interest!) any longer and are ready to transfer that balance to a 0% intro APR card that will treat you better. Also, don’t forget how important it is to make your payments on time every month — having a history of on-time payments is the most important factor used when calculating your credit score.