GST/PST Calculator (Canada)
Use this calculator to add or remove GST and PST from a price. Choose a province to auto-fill rates, or pick custom and enter your own values.
How to use this GST PST calculator
This GST/PST calculator is designed for fast, practical tax math. Whether you are preparing an invoice, checking a receipt, estimating a purchase, or reversing tax from a total, you can do it in seconds.
- Step 1: Enter an amount in CAD.
- Step 2: Choose whether the amount is before tax or tax-included.
- Step 3: Select a province/tax profile (or custom rates).
- Step 4: Click Calculate to see subtotal, GST, PST, and final total.
If you are working with a tax-included amount, the calculator can “back out” taxes so you can see the pre-tax price and each tax component clearly.
What are GST and PST?
GST (Goods and Services Tax)
GST is the federal sales tax in Canada. In many common examples, the GST rate is 5%. It applies to most goods and services unless a product is exempt or zero-rated under tax law.
PST (Provincial Sales Tax)
PST is a provincial-level sales tax used in some provinces. Some regions instead use HST (a harmonized tax), and Quebec uses QST terminology. Even when names differ, this calculator helps by separating a “federal” and “provincial” component so you can model totals clearly.
GST/PST formulas used by the calculator
When amount is before tax (non-compounded):
GST = Amount × GST rate
PST = Amount × PST rate
Total = Amount + GST + PST
When amount is tax-included (non-compounded):
Subtotal = Total ÷ (1 + GST rate + PST rate)
For advanced cases, you can enable compounding (PST calculated on amount + GST). This is uncommon in many day-to-day transactions, so use it only when your specific rules require it.
Example calculations
Example 1: Before-tax amount
Suppose your pre-tax amount is $100.00, with GST at 5% and PST at 7%:
- GST = $5.00
- PST = $7.00
- Total = $112.00
Example 2: Tax-included amount
Suppose the total paid is $112.00 and rates are GST 5% + PST 7%:
- Subtotal = 112 ÷ 1.12 = $100.00
- GST = $5.00
- PST = $7.00
This is useful for bookkeeping, purchase reconciliation, and receipt verification.
Common mistakes to avoid
- Using the wrong provincial rate: rates vary by province and can change over time.
- Confusing HST with separate GST/PST: some provinces use a single harmonized rate.
- Ignoring exemptions: some products and services may be exempt or taxed differently.
- Rounding too early: rounding line items too soon can create small invoice differences.
FAQ
Can I use this as a GST-only calculator?
Yes. Set PST to 0% and calculate normally.
Can I use this as a PST-only calculator?
Yes. Set GST to 0% and keep the PST value you need.
Does this calculator replace professional tax advice?
No. This tool is for estimation and general calculation. For legal compliance, filing, and product-specific tax rules, consult official CRA/provincial guidance or a tax professional.
Final note
A reliable GST PST calculator saves time, reduces invoice errors, and improves confidence when quoting or auditing totals. Keep this page bookmarked whenever you need a quick Canadian sales tax calculation.