GST/QST Calculator for Canada

Canada utilizes different tax frameworks depending on the province of supply. The calculation relies on adding applicable federal and provincial percentages to a base net price. The core formulas used are:

Gross Price = Net Price + (Net Price × GST) + (Net Price × PST) + (Net Price × HST)

Where individual tax portions are isolated as: Amount GST = Net Price × GST, Amount PST/QST = Net Price × PST, and Amount HST = Net Price × HST. For Quebec specifically, the Provincial Sales Tax acts as the QST, which is applied on top of the net price.

Imagine you run a business in Quebec and sell a consulting service for a net price of $1,000 before taxes. You need to calculate the federal Goods and Services Tax (GST at 5%) and the Quebec Sales Tax (QST at 9.975%). First, compute the GST: $1,000 × 0.05 = $50. Next, compute the QST: $1,000 × 0.09975 = $99.75. Adding these values together yields a total gross price of $1,000 + $50 + $99.75 = $1,149.75 for your client.

Always double-check the province of supply rules, as Canadian sales taxes are generally destination-based rather than origin-based. If you are a registered business, keep track of your Input Tax Credits (ITCs) to recover the GST/HST paid on business expenses. Finally, when performing reverse-calculations from a gross price back to a net price, remember to divide by the total multiplier (e.g., 1.14975 for Quebec) rather than simply subtracting the nominal tax percentages.