Built in Canada for Quebec businesses

GST QST Calculator Quebec 2026 — invoice taxes

Calculate 5% GST and 9.975% QST on each Quebec invoice line. Enter quantity and unit price to see subtotal, taxes, and total due.

Free tool for Quebec freelancers and small businesses who need correct GST/QST amounts before sending a PDF to clients.

Quebec calculator

Calculate GST and QST by line

GST 5% + QST 9.975%
LineQtyItem priceSubtotalGSTQSTTotalActions
1$10.00$0.50$1.00$11.50

Reference result for $1,000

In Quebec, both 5% GST and 9.975% QST are calculated on the pre-tax selling price.

Example: $1,000 before tax (registered for GST/QST)

Subtotal
$1,000.00
GST 5%
$50.00
QST 9.975%
$99.75
Total due
$1,149.75

Need a full template? See the Quebec invoice example.

Before adding the taxes to an invoice

This calculator checks the arithmetic; it does not determine whether a supply is taxable. Add only taxes your business is registered to collect, and confirm the treatment of exempt or zero-rated supplies.

Official sources: Revenu Québec tax calculation and GST/QST basic rules.

How GST and QST are calculated

For each line, the pre-tax amount is calculated as quantity multiplied by item price. GST and QST are then calculated separately on that subtotal.

  • Subtotal = quantity x item price
  • GST = subtotal x GST rate
  • QST = subtotal x QST rate
  • Total = subtotal + GST + QST

When to use this calculator

Use it to quickly check an invoice line, estimate a quote before sending it, or explain taxes to a client.

If you need to create a real invoice with your business details, tax numbers, and a PDF, use the invoice generator or review the Quebec invoice example and Canada invoice template.

Frequently asked questions

How do I calculate GST and QST on an invoice?

Multiply quantity by unit price for the pre-tax subtotal. Apply 5% GST and 9.975% QST to that subtotal, then add them together for the amount due.

When should I charge GST and QST?

In Quebec, you generally charge GST and QST when registered with the CRA and Revenu Québec. If you are not registered, do not add them to the invoice.

Can I create a PDF invoice after calculating?

Yes. Use the free invoice generator to add your business details, tax numbers, payment terms, and a professional PDF.

Create an invoice with GST and QST

Move from a quick calculation to a PDF invoice that is ready to send.

Create an invoiceSee an invoice exampleRead the GST/QST guide

Related guides

Go deeper with practical guides for invoicing, getting paid, and staying compliant in Canada.