How to Remove HST from a Price in Ontario
To remove HST from a price in Ontario, divide the total by 1.13 — that gives you the pre-tax amount.
Ontario charges 13% Harmonized Sales Tax on most purchases. When you have a receipt total and need the amount before tax — for bookkeeping, expense tracking, or claiming an Input Tax Credit — you reverse the calculation instead of multiplying by 13%.
The Reverse HST Formula
The formula is straightforward:
Pre-tax amount = Total ÷ 1.13
Once you have the pre-tax amount, you can find the HST portion in two ways: multiply the pre-tax amount by 0.13, or subtract the pre-tax amount from the total.
HST portion = Pre-tax amount × 0.13
Why 1.13? Ontario HST is 13% of the pre-tax price. A $100 item costs $113 after tax, so $113 ÷ 1.13 = $100. The divisor 1.13 represents the original price plus 13% tax baked in.
Worked Examples
Example 1 — $56.50 total: $56.50 ÷ 1.13 = $50.00 pre-tax. $50.00 × 0.13 = $6.50 HST. Check: $50.00 + $6.50 = $56.50.
Example 2 — $113.00 total: $113.00 ÷ 1.13 = $100.00 pre-tax. $100.00 × 0.13 = $13.00 HST. Check: $100.00 + $13.00 = $113.00.
Example 3 — $226.00 total: $226.00 ÷ 1.13 = $200.00 pre-tax. $200.00 × 0.13 = $26.00 HST. Check: $200.00 + $26.00 = $226.00.
Example 4 — $847.50 total: $847.50 ÷ 1.13 = $750.00 pre-tax. $750.00 × 0.13 = $97.50 HST. Check: $750.00 + $97.50 = $847.50.
What to Do with the Extracted HST
If you run a GST/HST-registered business, the HST you extract from business expenses is recoverable as an Input Tax Credit (ITC). Record the pre-tax amount as your expense and the HST portion as an ITC on your GST/HST return — it reduces what you owe the CRA.
If you are not registered for GST/HST, you cannot claim ITCs. The full amount you paid (including HST) is your cost. Reverse calculation still helps you understand how much tax was embedded in the price.
For freelancers and sole proprietors below the $30,000 small supplier threshold, registration is optional. Once you register voluntarily or exceed the threshold, ITCs on eligible business purchases become available.
What Is Exempt from HST in Ontario?
Not every Ontario purchase includes 13% HST. Common exemptions and zero-rated items include:
- Basic groceries (most food for human consumption)
- Prescription drugs and biologics
- Most medical devices and assistive technologies
- Residential rent and related services
- Most health and dental services
- Most financial services and insurance premiums
If a receipt shows no HST, the item may be exempt or zero-rated — do not apply the ÷ 1.13 formula to those totals.
Use the free reverse HST calculator to extract HST from any Ontario total instantly.
For the full Ontario HST reference including common amounts table and ITC rules, see the Ontario HST guide.
Calculations are arithmetic estimations only and do not constitute formal tax or corporate auditing advice. All figures must be verified against current CRA guidelines before filing.