® 
SBI charges interest rate only when the total bill amount due is not paid within the predetermined due date or the interest-free period. SBI credit card interest rate is the fee that is levied against your credit card when you use it to borrow funds for transactions.
For instance, if Rs. 8000 is the total amount due on your credit card and you pay a partial sum on the card, say Rs. 4000, the balance amount is added to the next billing cycle. In this scenario, the SBI credit card interest rate will be applicable.
How is the SBI Credit Card Interest Rate Calculated?
You can use the SBI credit card interest rate calculator to estimate the interest you will be charged on the balance due. The interest rate on the SBI credit card is calculated using the formula given below:
[Total number of days x transaction amount x 3.35% per month x 12 months x number of days] ÷ 365 days
What is the SBI Credit Card Interest-Free Period?
The State Bank of India provides a grace period, also called the interest-free period. This is the period from the transaction date till the payment due date. Generally, the credit card interest free period can be any number of days between 20 to 50. If you clear the outstanding amount before the payment due date, SBI will not charge interest on the transaction that you make.