Reverse sales tax calculator

Enter a tax-included amount to find the pre-tax price and the amount of each tax, anywhere in Canada.

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How to remove sales tax from an amount

To find the pre-tax price, divide the total by (1 + tax rate). A common mistake is to subtract 13% from the total, which gives a result that's too low.

Pre-tax amount = total ÷ (1 + rate)
Ontario: total ÷ 1.13
Quebec: total ÷ 1.14975

Why not just subtract the percentage? Because the tax was calculated on the pre-tax price, not on the total. Subtracting 13% from $113.00 gives $98.31, while the actual pre-tax price is $100.00.

Divisors by province

ProvinceRateDivide by
Quebec14.975%1.14975
Ontario13%1.13
British Columbia12%1.12
Alberta5%1.05
Manitoba12%1.12
Saskatchewan11%1.11
Nova Scotia14%1.14
New Brunswick15%1.15
Newfoundland and Labrador15%1.15
Prince Edward Island15%1.15
Yukon5%1.05
Northwest Territories5%1.05
Nunavut5%1.05

Examples in Ontario

Tax includedBefore taxTax
$10.00$8.85$1.15
$20.00$17.70$2.30
$50.00$44.25$5.75
$100.00$88.50$11.51
$200.00$176.99$23.01
$500.00$442.48$57.52
$1,000.00$884.96$115.04

When to use a reverse tax calculation

A reverse calculation is useful for filling out an expense report, entering an invoice in your bookkeeping, checking the tax on a receipt, or setting a tax-included selling price that lands on a round number, such as $20 all-in.

Frequently asked questions

How do I remove 13% HST from a price?
Divide the amount by 1.13. Don't subtract 13% from the total, since the rate applies to the pre-tax price, not the total.
How much tax is in $100 in Ontario?
$100 including HST is $88.50 before tax, with $11.50 of HST.
How do I remove GST and QST in Quebec?
Divide the total by 1.14975. For example, $114.98 ÷ 1.14975 = $100.00 before tax.

Sources

Rates and parameters checked against these sources in November 2026.

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