HST calculator
Add or remove HST in Ontario and the Atlantic provinces, where federal and provincial tax are combined.
Calculation mode
- Subtotal
- $100.00
- HST 13%
- $13.00
- Total
Get it on your phone
The same calculator, offline, with every province built in.
How it’s calculated
Adding tax to $100.00
Total = price × (1 + combined rate)
- Subtotal
- $100.00
- HST 13%
- $13.00
- Total
- $113.00
Removing tax from $100.00
Price = total ÷ (1 + combined rate)
- Subtotal
- $88.50
- HST 13%
- $11.50
- Total
- $100.00
Examples use Ontario at 13%. Change the province above to see another.
One tax instead of two
In a participating province, the provincial sales tax is harmonized with the federal GST into a single Harmonized Sales Tax. You calculate one number, show one tax line, and file one return with the CRA, which forwards the provincial share to the province.
Five provinces use it: Ontario and the four Atlantic provinces.
The rates are not all the same
This is the trap for anyone invoicing across the region. Nova Scotia decreased the provincial portion of its HST effective April 1, 2025, leaving it at 14%, while New Brunswick, Newfoundland and Labrador, and Prince Edward Island remain at 15% and Ontario is at 13%. A template with one hard-coded “Atlantic rate” will now be wrong somewhere.
On the invoice
The CRA asks that you show the total HST rate rather than breaking out the federal and provincial portions. Your customer needs the tax amount and your registration number to support their input tax credit claim.
Which rate applies
Place of supply decides, not where your business is located. A supply made in Ontario carries Ontario’s rate even if you’re based in Halifax. The rules treat goods, services and real property differently.
Pick a province above for its current rate and a worked example.
Common questions
Which provinces charge HST?
Ontario at 13%, Nova Scotia at 14%, and New Brunswick, Newfoundland and Labrador and Prince Edward Island at 15%.
Do HST provinces also charge GST?
No. HST already includes the federal portion, so you charge one combined rate, not GST on top.
Should an invoice show the federal and provincial parts separately?
No. The CRA asks that you show the total HST rate rather than splitting it.
Are all HST rates the same?
No. Nova Scotia lowered its provincial portion on April 1, 2025 and is now 14%, while the other Atlantic provinces remain at 15% and Ontario is 13%.
How do I reverse HST out of a total?
Divide the total by 1 plus the rate. In a 13% province, divide by 1.13.