Credit Card Interest Calculator
Credit card interest is charged on the balance every day, then billed monthly. Converting the annual APR into a monthly and daily figure shows how much of a payment is consumed before a single dollar of principal is repaid.
Monthly interest
$95.42
- Daily interest
- $3.14
- Annual interest
- $1,145.00
Values update as you type. This calculator covers the single scenario its formula assumes — see Common Mistakes for what it leaves out.
The formula this calculator uses
Monthly = Balance x APR / 12; Daily = Balance x APR / 365
- Balance
- Amount currently owed
- APR
- Annual percentage rate on the card
- Monthly
- Interest charged for one month
- Daily
- Interest accrued each day
How to check the result by hand
- 1
Find the balance
Use the current statement balance, which is the amount interest is charged on.
- 2
Find the APR
The annual rate is printed on the statement. Use the purchase rate, not a promotional rate that has expired.
- 3
Divide by twelve for a month
Balance times APR divided by twelve gives the interest for one month.
- 4
Divide by 365 for a day
The daily figure shows how quickly the debt grows between payments.
- 5
Multiply by the APR for a year
The annual figure is the cost of leaving the balance untouched for twelve months.
For worked examples, common mistakes and the limits of this formula, read the full How To Calculate Credit Card Interest page.