Free tool
GST & VAT calculator
Add GST, HST or VAT to a price, or work the tax out of a tax-inclusive total — with the CGST/SGST split for India and GST + QST for Quebec.
RESULT
- Price before tax
- $100.00
- Tax 10%
- $10.00
- Total including tax
- $110.00
Amounts are rounded to two decimals. PST and QST are provincial taxes with their own registration and rules on what's taxable.
How it works
- Adding tax: tax = price × rate ÷ 100, and total = price + tax.
- Removing tax from an inclusive price: tax = total × rate ÷ (100 + rate). At 10% that's one-eleventh; at 20%, one-sixth; at 5%, one-twenty-first.
- India: an intra-state sale splits the rate equally into CGST and SGST; an inter-state sale charges the full rate as IGST.
- Quebec: 5% GST and 9.975% QST are each calculated on the pre-tax price, and shown on separate lines.
StashBill does this automatically for every item and invoice. See all features or try the other free tools.
Frequently asked
Multiply the inclusive price by the rate and divide by (100 + rate). For 10% GST in Australia, that's the same as dividing by 11 — $110 includes $10 of GST.
Rates are as of October 2026: India 5%, 18% and 40% (since 22 September 2025), Australia 10%, UK 20% and 5%, UAE 5%, and Canada's provincial GST/HST rates including Nova Scotia's 14% HST since 1 April 2025. Always confirm the rate for your specific item with your tax authority.
It calculates one amount and rounds to two decimal places. On a multi-line invoice, pick one rounding method — per line or on the subtotal — and use it consistently.
Coming soon to Android, iOS, Windows & macOS
StashBill is in final development. It will be free forever for one device — no card required.