From APR to a monthly rate
Card interest is charged monthly, and the APR reflects that interest compounding over a year. The monthly rate is the rate that, compounded 12 times, equals the APR: (1 + APR)^(1/12) − 1.
Card providers usually work out interest on your daily balance, so your actual charge depends on when you spend and repay.
Worked example
A £2,000 balance on a card with a 24.9% APR has a monthly rate of about 1.87%, so a month's interest is about £37.40.
Avoiding interest
Paying your full balance by the due date each month usually means you pay no interest on purchases. Cash withdrawals often charge interest straight away.
Inputs for the calculator APR credit card
Card balance
The balance interest is charged on.
APR
Your card's annual percentage rate from your statement.
CALCULATOR QUESTIONS
Credit card APR calculator questions
How much interest will my credit card charge?
Roughly your balance times the monthly rate. For example, £2,000 at 24.9% APR is about £37.40 a month.
Is the monthly rate just the APR divided by 12?
Not quite. The APR includes compounding, so the monthly rate is a little lower than APR ÷ 12.
How can I avoid credit card interest?
Pay the full balance by the due date each month.
Do cash withdrawals cost more?
Usually. They often have a higher rate and interest from day one.