You received a total payment of $1,130 and need to know exactly how much of that is HST — and how much is your actual business income. Or perhaps you just paid $226 at checkout in Ontario and want to verify exactly what tax was charged. Finding the original base price requires a strict mathematical step backward. This page provides the exact calculation formulas, a complete 2026 Canadian province rate table, and a free calculator that does the math for you.
The Reverse HST Formulas
FORMULA 1 — Remove HST from a total (reverse calculation):
Original Price = Total Price ÷ (1 + HST Rate)
HST Amount = Total Price - Original Price
Example calculation (Ontario 13% HST):
- Total paid: $226.00
- HST rate: 13% = 0.13
- Original price = $226.00 ÷ 1.13 = $200.00
- HST paid = $226.00 - $200.00 = $26.00
FORMULA 2 — Add HST to a price (forward calculation):
Total with HST = Original Price × (1 + HST Rate)
How to Remove HST From a Total — Step by Step
Manually extracting HST is a three-step process. You cannot subtract the percentage directly from the final total — $226 minus 13% does not equal $200. You must reverse the original multiplication using division.
Step 1: Find your province HST rate
Consult the table below to find the specific tax rate for your Canadian province. If you are in Ontario, your rate is 13%. If you are in Nova Scotia, your rate is 14%.
Step 2: Divide the total by (1 + rate as decimal)
Convert your percentage rate to a decimal (13% becomes 0.13) and add 1 to get your divisor. For an Ontario transaction of $226.00, dividing by 1.13 gives you an exact original base price of $200.00.
Step 3: Subtract to find the HST amount
To find the exact dollar amount of the tax, subtract the original price from the final receipt total. In the Ontario example, $226.00 minus $200.00 means you paid exactly $26.00 in HST.
HST Rates by Province — Canada 2026 (Complete Reference Table)
Your calculations are only accurate if you use the correct regional tax rate. The divisor column below is the most critical piece of information — just divide your total by the divisor listed for your province.
| Province/Territory | Tax Type | Rate | Divisor to remove tax |
|---|---|---|---|
| Ontario | HST | 13% | ÷ 1.13 |
| New Brunswick | HST | 15% | ÷ 1.15 |
| Newfoundland | HST | 15% | ÷ 1.15 |
| Nova Scotia | HST | 14% | ÷ 1.14 |
| PEI | HST | 15% | ÷ 1.15 |
| British Columbia | GST+PST | 12% | ÷ 1.12 |
| Saskatchewan | GST+PST | 11% | ÷ 1.11 |
| Manitoba | GST+PST | 12% | ÷ 1.12 |
| Alberta | GST only | 5% | ÷ 1.05 |
| Quebec | GST+QST | 14.975% | ÷ 1.14975 |
| Yukon/NWT/Nunavut | GST only | 5% | ÷ 1.05 |
Try the Reverse HST Calculator Instantly
Open CalculatorQuebec GST/QST — How It Works Differently
If you live or do business in Quebec, you must account for the strict division between the 5% federal GST and the 9.975% provincial Quebec Sales Tax (QST). Unlike HST which is a single blended rate, Quebec charges GST and QST on the base price separately.
When you combine them, the total effective rate is 14.975%. Dividing a $114.975 final restaurant bill by 1.14975 leaves you with a clean $100.00 base charge. You can also read more about how to back out sales tax from any total for the core formula.
Frequently Asked Questions
How do I remove HST from a total in Ontario?
Ontario charges a 13% HST rate. To remove HST from a total, divide the final receipt amount by 1.13. For example, dividing a $113 grand total by 1.13 gives you a precise pre-tax total of $100.
What is the formula to back out 13% HST?
The mathematical formula to back out 13% HST is Original Price = Total Price ÷ 1.13. Subtracting the calculated original price from your total will reveal the exact 13% tax amount.
How do I reverse calculate HST in Nova Scotia in 2026?
Nova Scotia recently reduced its HST from 15% to 14%. To reverse calculate modern Nova Scotia HST, you must divide your total price by 1.14.
How to remove Quebec QST and GST from a total?
Quebec applies a 5% federal GST and a 9.975% provincial QST, creating an effective combined rate of 14.975%. To remove both taxes simultaneously, divide your total item cost by 1.14975.
Is HST the same in every Canadian province?
No, HST is not the same across Canada. Some provinces like Ontario charge 13% HST, maritime provinces like New Brunswick charge 15%, while others like Alberta only charge a 5% federal GST with no provincial component.
How do I calculate HST on an invoice for CRA reporting?
To isolate the exact HST amount to report to the Canada Revenue Agency, divide the gross invoice amount by 1 plus the provincial HST rate (e.g., 1.13). The remaining difference between the gross total and your result is the HST.
If you routinely process high volumes of invoices, manual math will eventually cause expensive remittance errors with the CRA. Manage your entire provincial workflow using our fast free reverse tax calculator.
Sources & Citations: Content verified against official guidelines from the IRS (US), HMRC (UK), and ATO (AU). Information is reviewed for accuracy prior to publication.
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