How to use
- Say whether GST is already in the price.
- Enter the amount and the GST rate, or tap a country.
- For India, choose within one state (CGST + SGST) or between states (IGST).
GST formula
Add GST: GST = amount × rate ÷ 100
Remove GST: amount before GST = price ÷ (1 + rate ÷ 100)
GST inside an inclusive price = price × rate ÷ (100 + rate)
At 18%, the GST inside a price is 18/118, or 9/59, of it.
Examples
- ₹1,000 plus 18% GST: GST is ₹180 and the total is ₹1,180. Within one state that is CGST ₹90 + SGST ₹90. Between states it is IGST ₹180.
- A$1,100 including GST: GST is one-eleventh, A$100 (business.gov.au example).
- NZ$115 including GST: 115 × 3 ÷ 23 = NZ$15 (Inland Revenue example).
India GST rates from 22 September 2025
| Rate | Used for | Within one state |
|---|---|---|
| 5% | Merit rate | 2.5% CGST + 2.5% SGST |
| 18% | Standard rate | 9% CGST + 9% SGST |
| 40% | Demerit rate for a select few goods and services | 20% CGST + 20% SGST |
| 3% | Gold, silver and jewellery | 1.5% CGST + 1.5% SGST |
- The 12% and 28% slabs were removed (PIB, 56th GST Council meeting).
- Since 1 February 2026, tobacco products and pan masala are at 40% and bidi at 18% (GST Council newsletter).
- The 57th meeting (8 October 2026) changed no slabs.
GST in other countries
| Country | Rate | GST inside an inclusive price |
|---|---|---|
| Australia | 10% | 1/11 |
| New Zealand | 15% | 3/23 |
| Singapore | 9% (since 1 January 2024) | 9/109 |
| Canada (GST) | 5% | 1/21 |
In Canada, some provinces charge one harmonized sales tax (HST) instead: Ontario 13%, Nova Scotia 14% (since 1 April 2025), and New Brunswick, Newfoundland and Labrador and Prince Edward Island 15% (CRA).
How rounding and the split work
We round the GST (when adding) or the amount before GST (when removing) to the paisa or cent. The other figure is the difference, so the parts always add up.
CGST is half the GST, rounded. SGST is the rest, so CGST + SGST always equals the IGST on the same amount. When the GST has an odd paisa, SGST shows one paisa less.
Charging VAT instead? Use the VAT calculator. For any other percentage, try the percentage calculator.