How it's calculated
GST is charged as a percentage of the price before GST. To add it, multiply; to take it out of a GST-inclusive price, divide by 1 plus the rate. Within one state the tax is split equally into central GST (CGST) and state GST (SGST, or UTGST in a union territory). On a sale from one state to another, the whole amount is integrated GST (IGST).
Since 22 September 2025, after the 56th GST Council meeting, most goods and services are taxed at 5% or 18%, with a 40% rate for tobacco, pan masala, sugary drinks and some luxury goods. Gold, silver and jewellery are at 3%, cut and polished diamonds at 1.5% and rough diamonds at 0.25%.GST Council The 12% and 28% rates were removed; tobacco products moved from 28% plus compensation cess to 40% on 1 February 2026.GST Council
The formula
- Adding GST: GST = price × rate; total = price × (1 + rate).
- Removing GST: price before GST = inclusive price ÷ (1 + rate); GST = inclusive price − price before GST.
- Within a state: CGST = SGST = GST ÷ 2. Between states: IGST = GST.
Worked example
GST at 18% on ₹10,000 is ₹1,800.00: ₹900.00 CGST and ₹900.00 SGST, for a total of ₹11,800.00.
| Line | Amount |
|---|---|
| Price excluding GST | ₹10,000.00 |
| CGST (9%) | ₹900.00 |
| SGST / UTGST (9%) | ₹900.00 |
| Price including GST | ₹11,800.00 |
Taking GST out of a price of ₹1,050 at 5% leaves ₹1,000.00 before GST and ₹50.00 of IGST.
Assumptions and limitations
- You choose the rate. The rate for a product or service depends on its HSN or SAC classification in the rate notifications; the examples next to each rate are only a guide.
- Some supplies are exempt or nil-rated, and some services are taxed under reverse charge, where the buyer pays the GST.
- Amounts are shown to the paisa. Invoices may round tax to the rupee.