Canadian sales tax is simple in principle and messy in practice: a 5% federal GST everywhere, harmonized into a single HST in five provinces, layered with separate provincial taxes (PST, RST, QST) in four others, and left alone in the territories and Alberta. This GST/HST calculator handles all of it. Pick your province, enter an amount, and choose direction — add tax to a pre-tax price, or reverse-calculate the pre-tax amount from a tax-included total (essential for expense claims and bookkeeping). The result breaks out each tax component separately, exactly the way it should appear on an invoice.
GST/HST Calculator (Canada)
Tax & Salary
Add or remove GST, HST, PST and QST for every province
Why GST/HST Calculator (Canada) Matters
Getting the provincial split right matters more than it looks. Businesses can generally claim input tax credits for GST/HST paid but not for BC, Saskatchewan, or Manitoba PST — so an invoice that lumps them together costs real money at filing time. Freelancers must register for GST/HST once revenues pass $30,000 over four consecutive quarters, and charging the wrong provincial rate on interprovincial sales is one of the most common CRA audit findings. As of 2026 the rates span from 5% in Alberta and the territories to 15% in New Brunswick, Newfoundland and PEI, with Nova Scotia at 14% following its April 2025 reduction.
The GST/HST Calculator (Canada) Formula, Explained
Total = Price × (1 + rate); reverse: Price = Total ÷ (1 + rate)The applicable rate is either the province's HST, or GST plus the provincial tax where they're separate. The reverse calculation is the one people get wrong: to remove 13% HST from a $113 total you divide by 1.13 (giving $100), you do not subtract 13% of $113 (which would wrongly give $98.31). Quebec's QST (9.975%) applies to the pre-tax price alongside GST, not on top of GST, since 2013.
How to Use the GST/HST Calculator (Canada): Step by Step
Enter the dollar amount you're working with
Enter the dollar amount you're working with.
Select the province or territory where the sale takes place
Select the province or territory where the sale takes place — for most goods, tax follows the buyer's delivery address.
Choose 'Add tax' if you have a pre-tax price, or 'Remove tax
Choose 'Add tax' if you have a pre-tax price, or 'Remove tax' to work backwards from a receipt total.
Read the total, the pre-tax price, and each tax component (G
Read the total, the pre-tax price, and each tax component (GST, PST/RST/QST, or HST) broken out separately.
Copy the component amounts to your invoice or expense report
Copy the component amounts to your invoice or expense report as needed.
GST/HST Calculator (Canada) Examples: Real-World Scenarios
1
Ontario HST
A $100 pre-tax purchase in Ontario (13% HST).
Amount:$100 pre-tax
Province:Ontario
Rate:13% HST
Calculation
HST = $100 × 13% = $13.00, so the total is $113.00. A single harmonized line item covers both the federal and provincial share.
Result
$113.00 total
2
Quebec GST + QST
A $100 pre-tax service billed in Quebec.
Amount:$100 pre-tax
Province:Quebec
Rates:5% GST + 9.975% QST
Calculation
GST = $100 × 5% = $5.00 and QST = $100 × 9.975% = $9.98, both computed on the pre-tax price. Total = $114.98, with two separate lines on the invoice.
Result
$114.98 total (combined 14.975%)
3
Reverse from a receipt
An Ontario receipt shows a $113.00 total; you need the pre-tax amount for an expense claim.
Amount:$113 total
Province:Ontario
Direction:Remove tax
Calculation
Pre-tax = $113 ÷ 1.13 = $100.00, so the HST recoverable as an input tax credit is $13.00. Dividing — not subtracting a percentage — is what makes this correct.
Result
$100.00 pre-tax, $13.00 HST
Common Mistakes to Avoid
- Reverse-calculating by subtracting the percentage from the total instead of dividing by (1 + rate).
- Charging your home province's rate on sales delivered to another province — place-of-supply rules generally follow the customer.
- Treating BC/SK/MB PST like GST for input tax credits: PST is a cost, not a recoverable credit, for most businesses.
- Using Nova Scotia's old 15% rate — it dropped to 14% on April 1, 2025.
- Forgetting that basic groceries and certain other goods are zero-rated or exempt, so no tax applies regardless of province.
Tips & Tricks
- Registering for GST/HST voluntarily below the $30,000 threshold lets you claim input tax credits — often worthwhile for B2B freelancers.
- Quote prices pre-tax in B2B contexts; business customers think net-of-tax because they recover GST/HST anyway.
- Keep the tax components separate in your accounting software from day one — untangling lumped totals at filing time is painful.
- For interprovincial e-commerce, configure tax by destination province, not your business address.
- Bookmark this page for reverse calculations at expense-report time — it's the most common real-world use.
One country, three tax systems: HST provinces, GST-plus-provincial provinces, and GST-only jurisdictions. The calculator keeps the rates and the reverse math straight so your invoices, claims, and filings are right the first time.
GST/HST Calculator (Canada) — Frequently Asked Questions
Related Calculators
Authoritative References
Canada Revenue Agency — GST/HST for businesses
canada.ca — Authoritative reference
CRA — GST/HST rates by province
canada.ca — Authoritative reference
External links open in a new tab. OmniCalc.us is not affiliated with these organisations.