GST Calculator

Add or remove Goods & Services Tax (GST) from a price. Works for India, Australia, Canada, New Zealand, Singapore and more — see the net amount, the GST, and the gross total instantly.

🧾

GST Calculator

Add or remove GST

$
%
GST Amount
Net (excl. GST)
Gross (incl. GST)
Net vs GST

How to Calculate GST

Goods and Services Tax (GST) is a value-added consumption tax used in many countries. To add GST to a net price, multiply by the rate: GST = net × rate, and the gross price = net + GST. To remove GST from a GST-inclusive price, divide: net = gross ÷ (1 + rate). At an 18% rate (India's standard slab), a ₹100 net price becomes ₹118, and a ₹118 inclusive price contains ₹18 of GST.

GST rates vary by country: India uses slabs of 5%, 12%, 18%, and 28%; Australia and Canada (GST portion) are flat; New Zealand is 15%; and Singapore is 9%. The most common mistake is removing GST by simply subtracting the rate from the gross — you must divide instead, because the rate was applied to the net, not the total. This calculator handles both directions accurately for any rate.

Adding GST

Gross = Net × (1 + rate). A $100 item at 10% GST costs $110, of which $10 is GST.

Removing GST

Net = Gross ÷ (1 + rate). A $110 inclusive price holds $10 GST — not $11. Always divide, never subtract the rate.

🌏

Rates by Country

India 5/12/18/28%, Australia 10%, Canada 5% (federal GST), NZ 15%, Singapore 9%. Tap a preset or enter your own.

FAQ

Multiply the net price by the GST rate to get the GST, then add it. At 18%: 100 × 0.18 = 18 GST, so the gross price is 118. Or simply multiply the net by 1.18. Choose "Add GST" above and the calculator does it for you.
Divide the GST-inclusive total by 1 plus the rate. At 18%, net = gross ÷ 1.18. So a 118 inclusive price has a net of 100 and contains 18 of GST. Don't subtract 18% of the gross — that gives the wrong answer.
They're essentially the same kind of multi-stage consumption tax under different names. "GST" is used in India, Australia, Canada, New Zealand, and Singapore; "VAT" is used across Europe, the UK, and much of the world. The math is identical — use whichever term applies in your country.

Related Calculators

✔ Reviewed by the True Value Calc editorial team🗓 Last updated June 2026📚 Sources: IRS.gov, U.S. Bureau of Labor Statistics