GST calculator

Questions people ask

How do I calculate GST on a price?

Multiply the price before GST by the rate and divide by 100. At 18%, GST on ₹10,000 is ₹1,800, so the invoice total is ₹11,800.

How do I remove GST from a price that already includes it?

Divide the total by (100 + rate) and multiply by 100 to get the price before GST. At 18%, ₹11,800 ÷ 118 × 100 = ₹10,000. The rest, ₹1,800, is the GST.

What is the difference between CGST, SGST and IGST?

A sale within one state carries CGST and SGST, each at half the rate (9% + 9% on an 18% item). A sale to another state carries IGST at the full rate (18%).

Which GST rates apply now?

Since 22 September 2025 the slabs are 0%, 5%, 18% and 40%. The 12% and 28% slabs were removed for supplies from that date, so older invoices can still show them. Some goods, such as precious metals, have special rates that this calculator doesn't list. Type any rate into the box.

Does the calculator round like the GST portal?

It rounds each tax head to two decimals, half up. Inside a state, CGST and SGST are each worked out on their own. When you take GST out of a total, an odd paisa goes to SGST so the heads add up to the tax.