The credit card interest calculator is a super easy to use credit card calculator that will allow you to calculate the credit card interest paid per month, the principal repaid per month, and the total amount of credit card interest paid over the life of the credit card repayment schedule. Just move the 3 slider arrows below and the calculations will automatically update! Once you have calculated your credit card interest then check out our low interest rate credit cards and also our full selection of credit cards on our home page!