Canada doesn't have one sales tax rate -- it has thirteen, one per province and territory, and they're built differently depending on where you are. Some provinces harmonize the federal and provincial tax into a single HST rate; others charge the federal GST plus a separate provincial sales tax on top; a few charge GST only. This calculator adds tax to a price or backs it out of a tax-inclusive total using the current combined rate for whichever province or territory you pick. It won't tell you which taxes apply to a specific product or service -- that depends on what you're selling -- but it gets the arithmetic right for the rate you select.
How it works
Pick a province or territory and the calculator looks up its current combined rate -- the GST/HST/PST/QST breakdown shown in the dropdown. In add mode, you enter a pre-tax price; the tax is the price times that rate, and the total is the price plus the tax. This is the calculation most people picture when they think "sales tax."
Remove mode solves the opposite problem. If a total already includes tax -- a receipt, a tax-inclusive listed price, a lump sum you collected -- you can't just subtract the rate from the total, because the rate was applied to the pre-tax price, not to the total itself. Instead, the total equals the pre-tax price times (1 + rate), so dividing the total by (1 + rate) recovers the original pre-tax price. The tax is whatever's left after subtracting that pre-tax price from the total.
For provinces that charge GST plus a separate provincial tax -- Quebec's QST, British Columbia's and Saskatchewan's PST, Manitoba's RST -- this calculator combines both into a single rate applied once to the same base (Quebec's 5% GST and 9.975% QST become one 14.975% rate, for example). That's the standard modern treatment and matches what you'll see on a receipt; it's simplified arithmetic, not a product-by-product tax determination.
Worked example
A $100 pre-tax price in Ontario (13% HST), in add mode:
- Sales tax: $100 x 13% = $13.00
- Total: $100 + $13.00 = $113.00
Now flip it: someone hands you a $200 total in Quebec that already includes the province's combined 14.975% rate (5% GST + 9.975% QST), and you need the pre-tax amount for your books. Divide, don't subtract:
- Pre-tax amount: $200 / 1.14975 = $173.95
- Sales tax: $200 - $173.95 = $26.05
Notice the tax isn't 14.975% of $200 (that would overstate it at $29.95) -- it's 14.975% of the pre-tax $173.95, which comes out to exactly $26.05 within rounding. That gap is why remove mode exists as its own calculation instead of a quick mental shortcut.
How to interpret your result
The number you want depends on why you're calculating. Quoting a client or pricing a product for a specific province: use add mode, pick that province, and the total is what you charge. Reconciling a receipt, extracting tax paid from a lump-sum reimbursement, or figuring out how much of a payout was tax collected on someone's behalf: use remove mode and the pre-tax amount is your real revenue figure, not the total.
Which province's rate applies depends on where the sale is considered to take place under GST/HST place-of-supply rules, which get more specific than "the buyer's province" for some goods and services. If you sell across multiple provinces, don't assume your own province's rate is always the right one -- verify the place-of-supply rule for the transaction in question.
Methodology & sources
Add mode: taxAmount = round2(amount x rate / 100), total = round2(amount + taxAmount). Remove mode: preTaxAmount = round2(amount / (1 + rate / 100)), taxAmount = round2(amount - preTaxAmount), with total equal to the tax-inclusive amount you entered. Provincial/territorial rates (combined, as of the date below):
- Alberta: 5% GST only
- British Columbia: 12% (5% GST + 7% PST)
- Manitoba: 12% (5% GST + 7% RST)
- New Brunswick: 15% HST
- Newfoundland and Labrador: 15% HST
- Nova Scotia: 14% HST (cut from 15% on April 1, 2025)
- Northwest Territories: 5% GST only
- Nunavut: 5% GST only
- Ontario: 13% HST
- Prince Edward Island: 15% HST
- Quebec: 14.975% (5% GST + 9.975% QST)
- Saskatchewan: 11% (5% GST + 6% PST)
- Yukon: 5% GST only
These figures were verified against the Canada Revenue Agency's official rate table on canada.ca: Charge and collect the GST/HST, as of 2026-07-08. Rates are set by provincial and federal governments and do change -- Nova Scotia's cut is the most recent example -- so re-check canada.ca before relying on this for a real invoice or filing. This tool does plain percentage arithmetic on a rate and amount you supply; it doesn't know your registration status, place-of-supply obligations, or which goods and services are zero-rated or exempt in your province, all of which affect what tax actually applies to a real sale. It is not tax advice.