Credit Card Interest Calculator
Calculate credit card interest on unpaid balances using APR and billing cycle. Free online calculator with daily periodic rate, charts, and payment analysis.
About This Calculator
This Credit Card Interest Calculator helps you estimate how much interest you will be charged on your unpaid credit card balance. Unlike simple interest calculators, it uses the daily periodic rate method that credit card issuers actually apply -- dividing your APR by 365 to get a daily rate, then multiplying by your balance and the number of days in your billing cycle.
Understanding how credit card interest works is essential for managing your finances. Credit cards typically have grace periods: if you pay your full statement balance by the due date, no interest is charged on new purchases. However, any unpaid balance carried to the next month accrues interest from the day of each transaction using the daily balance method.
Regional Notes
India: Credit card APRs in India range from 24% to 48% per annum depending on the issuer and card type. The RBI regulates credit card interest rates and requires issuers to clearly disclose APR and billing cycle details on monthly statements.
US: The average credit card APR in the US is approximately 22-24% as of 2025. The Credit CARD Act of 2009 requires issuers to provide a 21-day grace period and clear disclosure of interest calculation methods.
UK: UK credit card APRs typically range from 18% to 25% APR. The FCA regulates credit card practices and requires clear monthly statements showing interest calculations and minimum payment details.
Frequently Asked Questions
How is credit card interest calculated?
Credit card interest is calculated using the daily periodic rate method. The APR is divided by 365 to get the daily rate, which is then multiplied by your unpaid balance and the number of days in your billing cycle. The formula is: Interest = Balance x (APR / 365) x Days in Billing Cycle.
What is APR on a credit card?
APR stands for Annual Percentage Rate and represents the yearly cost of borrowing on your credit card. It includes the interest rate plus any additional fees. Most credit cards have variable APRs that can change based on market conditions, and different APRs may apply to purchases, cash advances, and balance transfers.
How can I avoid paying credit card interest?
You can avoid paying credit card interest by paying your full statement balance by the due date each month. Most cards offer a grace period between the end of the billing cycle and the payment due date. If you pay in full during this period, no interest is charged on new purchases.
What is a daily periodic rate on a credit card?
The daily periodic rate (DPR) is the APR divided by 365 days. For example, if your APR is 24%, the daily periodic rate is approximately 0.06575%. Credit card issuers use this daily rate to calculate interest on your unpaid balance each day.
Is this Credit Card Interest calculator free to use?
Yes, this calculator is completely free to use with no registration or sign-up required. Simply enter your balance, APR, and billing cycle days to get instant results.
How many days are in a typical credit card billing cycle?
Most credit card billing cycles are between 28 and 31 days, with 30 days being the most common. The exact number of days can vary by card issuer and month. You can find your billing cycle length on your monthly credit card statement.
What is the average credit card APR in India, US, and UK?
In India, credit card APRs typically range from 24% to 48% per annum. In the US, the average APR is around 22% to 24% as of 2025. In the UK, credit card interest rates average between 18% and 25% APR. Rates vary based on credit score, card type, and issuer.