Estimate credit card interest charges based on outstanding balance, APR, days, payments, and GST.
Credit Card Interest Calculator
The CardRatings credit card interest calculator offers a ballpark figure using a daily periodic rate calculation. It assumes a consistent APR and balance throughout the billing cycle. Your situation may vary depending on several factors including additional purchases or payments made throughout each cycle.
How do I use this calculator?
Enter your outstanding balance, your card’s annual interest rate (APR), and the number of days in your billing cycle. After inputting these values, the calculator will provide you with an estimate of your monthly interest charges, empowering you to make informed decisions about managing your credit card debt.
Estimate credit card interest charges based on outstanding balance, APR, days, payments, and GST.
Formula uses simple daily interest: Balance after payment × APR / 365 × days. Actual bank interest can differ because banks may use average daily balance, transaction dates, cash advance rules, late fees, and statement cycle logic.
Calculation Breakup
| Metric | Value | Meaning |
|---|---|---|
Daily Rate = APR / 365 / 100
Interest = Net Balance × Daily Rate × Number of Days
GST on Interest = Interest × GST Rate
Total Payable = Net Balance + Interest + GST on Interest