Canada GST/HST Calculator

Estimate Canadian sales tax by province using a practical calculator that supports before-tax amounts, after-tax totals, and tax breakdowns.

Calculation Mode*

Choose whether you are starting with a before-tax amount or an after-tax total.

Province or Territory*

Select the Canadian province or territory so the calculator can apply the appropriate GST, HST, PST, RST, or QST assumptions.

Amount*(currency)

Enter the amount that matches your selected workflow. Use a before-tax amount in the first workflow or a total-after-tax amount in the reverse workflow.

This Canada GST/HST calculator helps users estimate sales tax totals using province-appropriate assumptions for GST, HST, PST, RST, and QST where relevant. It supports two common workflows: starting with a before-tax amount to find the after-tax total, or starting with a total after tax to work backward to the before-tax amount. It also breaks out the tax layers so the result is easier to review and explain.

How It Works

Canada GST/HST Method

After-Tax Total = Before-Tax Amount x (1 + Combined Tax Rate); Before-Tax Amount = After-Tax Total / (1 + Combined Tax Rate)

The calculator applies province-based sales tax rates to move from a before-tax amount to an after-tax total, or reverses that process when you start with the after-tax total.

When you start with a before-tax amount, the calculator applies the province's combined sales tax assumption to estimate the full after-tax total.

When you start with a total after tax, the calculator divides the total by one plus the combined rate to recover the before-tax amount.

For HST provinces, the calculator treats the sales tax as a single harmonized layer.

For provinces with separate GST and provincial sales tax layers, the calculator shows the GST portion and the separate provincial portion in the breakdown.

Important Notes:

•This calculator is a practical Canada sales tax estimator, not tax filing or accounting software.
•Province and territory assumptions are based on current standard published GST, HST, PST, RST, and QST rates used for straightforward planning scenarios.
•Some real transactions may be tax-exempt, zero-rated, or subject to special rules that this first version does not model.
•Quebec is shown using a separate provincial tax layer for practical planning even though the provincial component is QST rather than PST.
•This tool is best for estimate-based budgeting, invoice checks, and quick tax math.

Worked Example

A user in Ontario wants to estimate the total cost of a $100 purchase before tax.

Inputs:

calculation Mode:beforeTaxToTotal
province Code:ON
amount:100

Result:

The calculator shows a before-tax amount of $100, HST of about $13, total tax of about $13, and a total after tax of about $113.

Who Is This Calculator For?

canadian shoppers
freelancers
small businesses
invoice planners
canada personal finance users

Frequently Asked Questions

GST is the federal goods and services tax. HST is a harmonized sales tax used in some provinces instead of separate federal and provincial sales taxes. PST is a separate provincial sales tax layer used in some provinces alongside GST.

Because provinces do not all use the same sales tax structure. Some use HST, some use GST plus a separate provincial tax, and some use only GST.

Yes. Choose the reverse workflow and enter the after-tax total. The calculator will estimate the before-tax amount and tax breakdown using the province you selected.

Because Quebec uses GST plus QST rather than HST. This calculator shows the provincial layer separately for practical planning and breakdown clarity.

It is useful for quick planning and checks, but real invoices and tax reporting can depend on product rules, exemptions, and business registration details.