How this calculator works
Rates are the general rates checked November 1, 2026. Quebec uses 5% GST and 9.975% QST on the same before-tax amount. HST replaces separate GST in participating provinces; Nova Scotia uses 14% from April 1, 2025. Provincial exemptions and special product rates are excluded. Compute first, then round each component as required by your invoice system.
Formula
Total tax = net x (GST rate + provincial rate + HST rate). Gross = net x (1 + combined rate). QST is calculated on net, not on net plus GST.
Worked example
In Quebec a $100 base has $5 GST and $9.975 QST, giving $114.975 before invoice rounding. In Nova Scotia a $100 base has $14 HST and a $114 total.
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Frequently asked questions
Is QST applied to GST?
No. The current general calculation applies GST and QST to the same before-tax price.
Can I reverse a receipt total?
Yes. Choose tax-inclusive price. You may also start from a separate tax component if it exists in that province.
Why can my receipt differ by a cent?
Retailers can round line items and tax components separately. This calculator keeps precision until display.