How to Calculate GST: Add It, Remove It and Split It

GST is a percentage added to the price of most goods and services in India. Once you know the rate, the sums are short.

To add GST, multiply the price by the rate and add the result. At 18%, GST on ₹1,000 is ₹180, so the customer pays ₹1,180.

To remove GST from a total, divide by 1 plus the rate. At 18%, ₹1,180 divided by 1.18 gives ₹1,000. A common mistake is to take 18% off the total, which gives the wrong answer because the tax was worked out on the lower price.

Within a state, the tax splits equally into CGST and SGST, so 18% becomes 9% and 9%. Between states, the full rate is charged as IGST.

Check the rate that applies to your goods or services, because it varies. Our GST calculator does each of these sums and shows every line.