GST Calculator (India)

To calculate GST, multiply the amount by the GST rate: GST = Amount × Rate ÷ 100. For an intra-state sale the GST is split equally into CGST and SGST; for an inter-state sale the whole amount is IGST. Enter an amount below to add GST to a price, or remove GST from a GST-inclusive price — the CGST/SGST/IGST split is worked out automatically at the current 2026 slabs (Nil, 5%, 18%, 40%).

Amount (₹) GST rate Calculation Supply type

Base (taxable) value—

CGST—

SGST—

IGST—

Total GST—

Total amount—

How GST is calculated

Add GST (price is exclusive): GST = Amount × Rate ÷ 100. Total = Amount + GST.
Remove GST (price is inclusive): Base = Amount ÷ (1 + Rate ÷ 100). GST included = Amount − Base.
Intra-state (buyer in your state): CGST = SGST = GST ÷ 2.
Inter-state (buyer in another state): the full GST is IGST.

The total tax is the same either way — 18% is either 9% CGST + 9% SGST or a single 18% IGST. Only the split between the Centre and the State changes.

Worked example

A ₹10,000 sale at 18%, intra-state: GST = 10,000 × 18 ÷ 100 = ₹1,800, split as ₹900 CGST + ₹900 SGST, for a total invoice of ₹11,800. If ₹11,800 were GST-inclusive instead, the base would be 11,800 ÷ 1.18 = ₹10,000 and the GST ₹1,800.

Which GST rate should I use?

Since 22 September 2025, India's GST has four main slabs — Nil, 5%, 18% and 40% (the 12% and 28% slabs were abolished). Rates are item-specific, so confirm the exact rate for your product's HSN/SAC code on the official CBIC rate finder. See GST rates 2026 explained.

Frequently asked questions

What is the formula to calculate GST? GST = Amount × Rate ÷ 100. Add it to the base for a GST-exclusive price, or divide the total by (1 + Rate ÷ 100) to remove GST from a GST-inclusive price.

How is GST split into CGST and SGST? For a sale within your own state, GST is split equally: half is CGST and half is SGST. For a sale to another state, the whole amount is IGST instead.

What are the GST rates in 2026? Nil, 5%, 18% and 40% are the four main slabs, plus special rates like 3% on gold. The 12% and 28% slabs were removed on 22 September 2025.

How do I remove GST from a total? Divide the GST-inclusive amount by (1 + Rate ÷ 100) to get the base value, then subtract it to get the GST. For example, ₹1,180 ÷ 1.18 = ₹1,000 base and ₹180 GST at 18%.

Sources

CGST Act & IGST Act (CGST/SGST/IGST mechanism); CBIC GST rate notifications effective 22 September 2025 — cbic-gst.gov.in.

General information, not professional advice. Verify the rate for your HSN/SAC on the official CBIC rate finder. See our Disclaimer.