GST Calculator

How GST is worked out

Choose GST Exclusive when your amount is the price before tax. The GST is the amount times the rate, and the total is the two added together: ₹1,000 at 18% is ₹180 of GST and ₹1,180 in all.

Choose GST Inclusive when your amount already includes tax, such as a price on a bill. The price before GST is the amount times 100, divided by 100 plus the rate: ₹1,180 at 18% is ₹1,000 plus ₹180 of GST.

CGST and SGST, or IGST?

A sale within one state is taxed as CGST and SGST, each at half the rate, so 18% becomes 9% + 9%. A sale from one state to another is taxed as IGST at the full rate. The total tax is the same either way; only the split between the centre and the state differs. The calculator shows both, so you do not have to decide first.

Which rate applies?

Since the rate changes of September 2025, most goods and services are taxed at 5% or 18%, with 40% for a small group of luxury and sin goods. A few items carry other rates, so check the rate for your product or service before you bill.

Rounding

Every amount is rounded to the paisa. When the GST splits into CGST and SGST, the two halves always add up to the GST shown.