The one rule to remember
Price before tax = total ÷ (1 + tax rate). In Ontario that is total ÷ 1.13.
Example: a receipt for $565.00 in Ontario. $565 ÷ 1.13 = $500.00 before tax, and the HST is $565 − $500 = $65.00.
Why subtracting 13% gives the wrong answer
The tax was added to the smaller pre-tax price. If you take 13% off $565 you get $491.55 — almost $8.50 too low. The tax share of a tax-included total is actually 13 ÷ 113 = about 11.5%.
Divisors by province
| Province | Divide the total by | Tax share of the total |
|---|---|---|
| Ontario | 1.13 | 11.50% |
| Nova Scotia | 1.14 | 12.28% |
| New Brunswick, Newfoundland and Labrador, PEI | 1.15 | 13.04% |
| Quebec | 1.14975 | 13.02% |
| British Columbia, Manitoba | 1.12 | 10.71% |
| Saskatchewan | 1.11 | 9.91% |
| Alberta and the territories | 1.05 | 4.76% |
Ontario totals worked backwards
| Receipt total | Before tax | HST included |
|---|---|---|
| $11.30 | $10.00 | $1.30 |
| $56.50 | $50.00 | $6.50 |
| $113.00 | $100.00 | $13.00 |
| $226.00 | $200.00 | $26.00 |
| $565.00 | $500.00 | $65.00 |
| $1,130.00 | $1,000.00 | $130.00 |
| $2,260.00 | $2,000.00 | $260.00 |
| $5,650.00 | $5,000.00 | $650.00 |
Splitting GST and PST when they are separate
In B.C. or Manitoba, first find the pre-tax price (total ÷ 1.12), then multiply by 5% for GST and 7% for PST. A $112 receipt is $100 + $5 GST + $7 PST. In Quebec, divide by 1.14975, then GST = 5% and QST = 9.975% of that price.
When you need this
- Business expenses: a GST/HST registrant claims the tax part as an input tax credit, so the books need the split.
- Employee expense claims sometimes ask for the pre-tax amount.
- Price checks: comparing a tax-included price from one province with a pre-tax price from another.
Small rounding differences of a cent are normal: stores round tax on each receipt, not on each item.
Quick reference: sales tax mistakes to avoid
- Subtracting the rate from a total. Always divide by 1 + rate to go backwards.
- Using your home province for online orders. Tax follows the delivery address, not where you or the seller live.
- Adding PST on top of GST-included prices. In B.C., Saskatchewan, Manitoba and Quebec both taxes are calculated on the pre-tax price, never one on top of the other.
- Forgetting zero-rated items. A grocery receipt often mixes taxable snacks with tax-free basics, so the total tax is rarely a neat 13%.
- Rounding item by item. Stores calculate tax on the receipt subtotal, so your own sum can differ by a cent.
For small businesses and freelancers
You must register for a GST/HST account once your worldwide taxable sales pass $30,000 in a single calendar quarter or over four consecutive quarters (the “small supplier” limit). Before that, registering is optional — some freelancers register early so they can claim back the GST/HST they pay on equipment and software. Once registered, you charge the rate of the customer’s province, file returns (annually, quarterly or monthly) and keep receipts for six years. Quebec businesses also register for the QST with Revenu Québec, and B.C., Saskatchewan and Manitoba each have their own PST registration rules.
Rates in this guide were checked against the CRA’s GST/HST rate table on 5 November 2026; provincial budgets can change PST rates, usually with a few weeks’ notice.
FAQ
How do I calculate the amount before HST?
Divide the total by 1 plus the rate. In Ontario: total ÷ 1.13. $565 ÷ 1.13 = $500.00, so the HST is $65.00.
Why can’t I just subtract 13%?
Because the 13% was added to the smaller pre-tax price. Taking 13% off $565 gives $491.55 instead of the correct $500.00.
How do I remove 5% GST from a total?
Divide by 1.05. A $105 receipt in Alberta is $100.00 plus $5.00 GST.
Sources (checked 5 November 2026): Canada Revenue Agency, “GST/HST provincial rates table” (canada.ca, 13% Ontario, 14% Nova Scotia from April 1, 2025, 15% NB/NL/PE); Revenu Québec, QST rate 9.975%; B.C. Ministry of Finance, PST 7%; Saskatchewan PST 6%; Manitoba RST 7%; cross-checked with TaxTips.ca “2026 sales tax rates” (revised Aug 28, 2026).