GST vs HST — which rate applies?
Canada uses GST (Goods and Services Tax) at 5% federally. Several provinces combine federal and provincial tax into HST (Harmonized Sales Tax) — commonly 13% in Ontario and 15% in Nova Scotia, New Brunswick, and Newfoundland and Labrador. Other provinces may charge GST plus PST separately; on a single-line invoice you often use one combined percentage.
Formulas for GST tax invoice calculation
From net: Tax = Net × (Rate ÷ 100)
Total: Gross = Net + Tax = Net × (1 + Rate/100)
From gross: Net = Gross ÷ (1 + Rate/100)
Worked examples
| Rate | Net | Tax | Total |
|---|---|---|---|
| 5% GST | CA$1,000 | CA$50 | CA$1,050 |
| 13% HST (Ontario) | CA$1,000 | CA$130 | CA$1,130 |
| 15% HST (Atlantic) | CA$1,000 | CA$150 | CA$1,150 |
Step-by-step on a real invoice
- 1
List each line item: quantity × unit price = line total.
- 2
Sum line totals to get the subtotal (net amount).
- 3
Multiply subtotal by your GST/HST rate for the tax line.
- 4
Add subtotal + tax for total due. Show all three on the invoice in CAD.