A goods and services tax (GST) is a value-added tax charged on most sales and collected by the seller. Whether you are issuing an invoice or checking a receipt, you usually need one of two conversions: add GST to a net price, or pull GST out of a price that already includes it. This calculator does both and includes the current standard rates for the countries that most often search for them.
How to use the GST calculator
- Choose Add GST (you have the net price) or Remove GST (you have the GST-inclusive price).
- Enter the amount.
- Pick a country and rate preset, or choose Other rate and type any GST or VAT rate.
- Read the net, GST and gross amounts on the tape. For India the tape also shows the CGST/SGST split; for Canadian HST it shows the federal and provincial parts.
GST formulas
Worked examples
India, 18%, adding GST. Net ₹1,000 → GST = ₹180 → gross ₹1,180. Within one state that is CGST ₹90 + SGST ₹90; between states it is IGST ₹180.
Australia, 10%, removing GST. Gross A$110 → net = 110 ÷ 1.10 = A$100 → GST A$10 (one-eleventh of the price).
Ontario HST, 13%, removing tax. Gross C$113 → net C$100 → HST C$13, of which C$5 is the federal GST and C$8 the provincial part.
Current GST rates in the presets
| Country | Rate(s) | Notes |
|---|---|---|
| India | 5%, 18%, 40% | GST 2.0 slabs from 22 September 2025; 12% and 28% retired |
| Australia | 10% | Basic food, most health and education are GST-free |
| Canada | 5% GST; 13%–15% HST | HST in ON (13%), NS (14% from 1 April 2025), NB, NL, PEI (15%) |
| New Zealand | 15% | Applies to most goods and services |
| Singapore | 9% | Since 1 January 2024 |
Rates were checked against the Canada Revenue Agency and government announcements in October 2026. Many products carry zero-rated or exempt treatment, so always confirm the rate for the specific item or HSN/SAC code.
Common GST mistakes
Subtracting the rate from the inclusive price
Taking 18% off ₹1,180 gives ₹967.60, not ₹1,000. GST was calculated on the net amount, so you must divide by 1.18 to reverse it.
Mixing up place of supply in India
Charging CGST and SGST on an inter-state sale, or IGST on an intra-state sale, is a common invoicing error. The total tax is the same, but it is credited to different governments.
Forgetting provincial sales tax in Canada
In British Columbia, Manitoba, Saskatchewan and Quebec, a separate provincial sales tax applies on top of the 5% GST. Choose Other rate and enter the combined rate if you need the full amount.
For US sales tax, use the sales tax calculator or the reverse sales tax calculator. To compare prices across currencies, try the currency converter.
Rates and results are estimates for general guidance and are not tax advice. Check your tax authority (CBIC, ATO, CRA, IRD or IRAS) for the rate that applies to a specific supply.
Frequently asked questions
How do I add GST to a price?
Multiply the net price by the GST rate as a decimal and add the result. At 18%, GST on ₹1,000 is ₹180 and the GST-inclusive price is ₹1,180. Multiplying by 1.18 gives the same total in one step.
How do I remove GST from a GST-inclusive price?
Divide the inclusive price by 1 plus the rate. At 10% in Australia, A$110 ÷ 1.10 = A$100, so the GST is A$10 — one-eleventh of the inclusive price. At New Zealand's 15%, the GST is 3/23 of the inclusive price.
What are the current GST rates in India?
Since 22 September 2025, India's main GST rates are 5% for essentials and many everyday goods, 18% as the standard rate, and a special 40% rate for luxury and sin goods. The older 12% and 28% slabs were removed; they remain in the calculator only for checking earlier invoices.
What is the difference between CGST, SGST and IGST?
For a sale within one Indian state, GST is split equally between the central government (CGST) and the state (SGST, or UTGST in a union territory). For a sale between states, a single integrated tax (IGST) at the full rate applies.
What is HST in Canada?
The Harmonized Sales Tax combines the 5% federal GST with a provincial portion in participating provinces: 13% in Ontario, 14% in Nova Scotia and 15% in New Brunswick, Newfoundland and Labrador and Prince Edward Island.