Credit Card Interest Calculator
Free credit card interest calculator: enter a balance, APR, and monthly payment to see your payoff date, the total interest the card will cost you, and how much of your first payment interest eats.
Frequently asked questions
How is credit card interest calculated?
Your card's APR is divided by 12 to get a monthly rate, which is charged on your remaining balance each month. Paying a fixed amount above the minimum shrinks the balance faster than the interest can grow it.
What happens if my payment is less than the monthly interest?
The balance grows instead of shrinking, and the card would never be paid off. This calculator flags that case — the results show your first month's interest, and your payment needs to be above it.
Does paying twice a month help?
Slightly: splitting the same total into two payments can lower the average balance interest is charged on. The bigger win is raising the total monthly amount — even $50 more a month can cut months of interest.
This page is educational and is not financial, tax, or legal advice. See our disclaimer.