Credit Card Interest Calculator — Real Cost + GST | Techovra
Credit Card Interest Calculator
See the interest and GST a carried balance costs you, and how long it takes to clear.
Calculate Your Credit Card Finance Charge
Enter your balance and your issuer's monthly rate. Results update as you type.
Credit cards feel free as long as you clear the bill in full every month. The moment you don't, they become the most expensive form of everyday borrowing available in India, well above even the priciest personal loan. This credit card interest calculator shows you exactly what carrying a balance actually costs, including the GST most people forget gets added on top. Our guide on the real annual cost of credit card interest lays out the same numbers across a full year.
How is credit card interest calculated?
Banks charge interest on the unpaid balance from the transaction date, not the due date, using a monthly percentage rate, and then add 18% GST on top of the interest itself. The formula for a single month:
GST on interest = Interest × 18%
Total finance charge = Interest + GST
Credit card interest rate India: the real range
As of August 2026, credit card interest rates from major Indian issuers run roughly 2.5% to 3.75% per month, which is 30% to 45% annualised. HDFC Bank's published range is 1.99% to 3.75% per month; SBI Card runs up to 3.75% per month; ICICI Bank's range is 3.40% to 3.67% per month. Where you land within that range depends on your card type and your relationship with the issuer, but even the lowest end of that range is far above any secured or unsecured loan rate on this site.
A worked example
Say you have an outstanding balance of ₹40,000 on your credit card that you don't clear by the due date, and your issuer charges 3.5% per month. This credit card finance charge calculator is pre-filled with those numbers.
- Interest: ₹40,000 × 3.5% = ₹1,400.
- GST on interest: ₹1,400 × 18% = ₹252.
- Total finance charge: ₹1,400 + ₹252 = ₹1,652.
That's ₹1,652 added to your bill for one month of carrying ₹40,000, and if you don't clear the balance the following month either, interest starts accruing on the new, larger outstanding amount. Run the calculator with your own balance and issuer's rate to see exactly what a carried balance is costing you. If you want to know how much of each statement you have to send just to keep the account current, our credit card minimum payment calculator shows why that minimum due barely dents the balance.
Why this rate makes credit cards the worst place to carry debt
At 30%-45% p.a., credit card debt costs roughly three to four times what a personal loan costs, and eight to ten times what a home loan costs, for the exact same rupee amount. If you're ever choosing between paying off a credit card balance or a lower-rate loan first, the credit card should almost always win. See our debt payoff calculator for the full comparison across multiple debts.
Frequently Asked Questions
Why does interest start from the transaction date and not the due date?
Once you carry any part of your balance past the due date, most Indian issuers withdraw the interest-free period for that entire billing cycle and charge interest on every transaction from the date it was made, not just the unpaid portion. This is one of the more misunderstood parts of credit card billing.
Does paying off part of the balance reduce the interest?
Yes. Interest is calculated on the outstanding balance, so any payment above the minimum due reduces what you're charged interest on going forward. It won't restore your interest-free period for the current cycle, but it does reduce every subsequent month's finance charge.
This shows you the interest math. Your card issuer's exact rate, GST treatment and billing cycle rules govern your actual statement.