GST Calculator
Add or remove GST on one price or a whole bill, with current rates for India (CGST/SGST), Canada, Australia, NZ, Singapore and Pakistan.
By Syed Mubashir Ali · Last updated
Estimates only — not financial advice. Figures are calculated in your browser from the rates shown and may differ from your bank, lender or tax authority. Check important numbers before acting on them.
The mistakes that cost real money
Mistake one is subtracting the rate instead of dividing: taking '18% off' ₹1,180 gives ₹967.60, but the true pre-tax price is ₹1,000: a ₹32.40 error per thousand that compounds across an invoice. Mistake two is applying one rate to a mixed bill: if half your items are 5% and half 18%, a blended guess is always wrong. Enter each line separately.
Mistake three is specific to India: charging CGST+SGST on an inter-state sale (or IGST on an intra-state one). The place of supply rules decide which applies, and getting it wrong means the invoice doesn't match the GST return. The calculator's 'The sale is' switch applies the standard rule (within a state, CGST + SGST; between states, IGST), but your accountant has the final word on edge cases.
How to Use GST Calculator
- 1Choose the country: India, Pakistan, Australia, New Zealand, Canada (then your province) or Singapore. That sets its GST rates; pick 'Other' to use any rate.
- 2Say whether the prices you'll enter are before GST (to add it) or already include it (to take it out).
- 3Enter the amount and rate. For a whole bill or invoice, add an item for each line, with its own quantity and rate.
- 4In India, choose a sale within a state to split the tax into CGST and SGST, or between states for IGST.
- 5Read the amount before tax, the GST and the total, with a breakdown by rate. Copy or share the result.
Frequently Asked Questions
How do I calculate GST?
Multiply the price by the rate. At 18%, GST on ₹1,000 is ₹180, so the total is ₹1,180. For a whole invoice, work out each line at its own rate and add them: ₹200 of goods at 5% plus ₹300 at 18% is ₹10 + ₹54 = ₹64 GST.
How do I remove GST from a price that includes it?
Divide by 1 plus the rate. ₹1,180 including 18% GST is ₹1,180 ÷ 1.18 = ₹1,000 before tax, with ₹180 GST. Taking 18% off ₹1,180 gives ₹212.40, which is wrong. In Australia, where GST is 10%, the GST in a price is one eleventh: A$110 includes A$10.
What are the GST rates in India now?
Since 22 September 2025, most goods and services are taxed at 5% or 18%, with 40% for luxury and 'sin' goods such as large cars, 3% for gold and 0% for many essentials. The old 12% and 28% slabs were merged into these. Check your item's HSN or SAC code for its exact rate.
What is the difference between CGST, SGST and IGST?
They're how India splits GST between the centre and the states. On a sale within one state, half goes to the centre as CGST and half to the state as SGST: 18% GST on ₹1,000 is ₹90 CGST + ₹90 SGST. On a sale between states, the whole ₹180 is IGST.
What are the GST/HST rates in Canada?
5% GST in Alberta, the territories, and in British Columbia, Manitoba, Quebec and Saskatchewan (which add their own provincial sales tax). HST is 13% in Ontario, 14% in Nova Scotia (cut from 15% on 1 April 2025) and 15% in New Brunswick, Newfoundland and Labrador and Prince Edward Island.
What are the GST rates in Australia, New Zealand, Singapore and Pakistan?
Australia 10%, New Zealand 15% and Singapore 9% (since January 2024). Pakistan's standard federal sales tax on goods is 18%; services are taxed by the provinces.
Do I charge GST on shipping?
Generally yes, at the same rate as the goods: shipping is part of the taxable supply in most GST systems. In India, freight charged on an invoice attracts GST at the rate of the goods. If shipping is billed entirely separately by a third party, that party's own GST treatment applies.
About GST Calculator
This GST calculator adds GST to a price or takes it out of a price that already includes it, for a single amount or a whole bill. Each line can have its own quantity and rate, so a mixed invoice (some items at 5%, others at 18%) is worked out correctly, with the tax shown per rate.
Country presets carry the current rates for India, Pakistan, Australia, New Zealand, Canada (by province, including HST) and Singapore, checked against each tax authority. For India it splits the tax into CGST and SGST for sales within a state, or shows IGST for sales between states, the way a GST invoice lays it out.
Removing GST is where most mistakes happen: you divide by 1 plus the rate, you don't subtract the rate. The calculator does this for you and explains it under 'How we calculate'. Which rate applies depends on how your goods or service are classified, so check that with the tax authority or an accountant.