Why is Quebec's combined rate 14.975% instead of 14.975% (5% + 9.975%)?

Quebec's QST is calculated on the GST-inclusive amount. So $100 + $5 GST = $105, and QST = $105 × 9.975% = $10.474. Total tax is $15.474, which is 15.474% of the original $100. The math is also expressible as an effective rate of about 15.47%, but most retailers quote it as "5% + 9.975%".

What about HST on services from another province?

The "place of supply" rules determine which province's rate applies, and they're not always simple. For a service delivered remotely to a customer in another province, you generally charge the rate of the customer's province. CRA has detailed guidance on this; check it for your specific situation.

Are there exemptions?

Many — basic groceries, prescription drugs, most medical devices, residential rent, and certain financial services are GST/HST-exempt or zero-rated. The CRA's "GST/HST for businesses" pages cover the full list.

Why is my rounded total off by a cent?

Floating-point math plus per-line rounding. Real point-of-sale systems round each line item to 2 decimal places before summing, which can produce a different total than tax on the line subtotal. This tool computes the exact mathematical answer; minor cent-level differences are normal.

GST / HST / PST Calculator

Calculate Canadian sales taxes by province. Forward and reverse calculations for GST, HST, PST, and QST.

Runs entirely in your browser. Nothing is sent to our servers.

About this tool

Calculates Canadian sales tax for every province and territory. Works in both directions — add tax to a pre-tax price, or back out the pre-tax amount from a total. Reflects 2026 rates including the Nova Scotia HST reduction (15% → 14% on April 1, 2025).

How sales tax works in Canada

GST (Goods and Services Tax) is the 5% federal tax, applied in provinces that don't use HST.
HST (Harmonized Sales Tax) combines federal GST and provincial tax into a single rate, in ON (13%), NS (14%), NB/NL/PE (15% each).
PST (Provincial Sales Tax) is charged separately on top of GST in BC (7%), SK (6%), MB (7%). Some provinces call it RST or QST.
QST (Quebec Sales Tax) is 9.975%, calculated on the GST-inclusive amount — making the effective combined rate 14.975%.
AB, YT, NT, NU have no provincial sales tax. You pay only the 5% federal GST.

Frequently asked questions

Why is Quebec's combined rate 14.975% instead of 14.975% (5% + 9.975%)?: Quebec's QST is calculated on the GST-inclusive amount. So $100 + $5 GST = $105, and QST = $105 × 9.975% = $10.474. Total tax is $15.474, which is 15.474% of the original $100. The math is also expressible as an effective rate of about 15.47%, but most retailers quote it as "5% + 9.975%".
What about HST on services from another province?: The "place of supply" rules determine which province's rate applies, and they're not always simple. For a service delivered remotely to a customer in another province, you generally charge the rate of the customer's province. CRA has detailed guidance on this; check it for your specific situation.
Are there exemptions?: Many — basic groceries, prescription drugs, most medical devices, residential rent, and certain financial services are GST/HST-exempt or zero-rated. The CRA's "GST/HST for businesses" pages cover the full list.
Why is my rounded total off by a cent?: Floating-point math plus per-line rounding. Real point-of-sale systems round each line item to 2 decimal places before summing, which can produce a different total than tax on the line subtotal. This tool computes the exact mathematical answer; minor cent-level differences are normal.

Last updated: May 17, 2026

About this tool

How sales tax works in Canada

Frequently asked questions

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