Free · add or remove 13% · private

Ontario HST calculator: add or remove 13% tax.

Calculate Ontario’s current general 13% HST from a before-tax amount, or work backward from a tax-included total. The amount stays in your browser, with the subtotal, HST, and total shown separately.

All provinces and territories

Add or remove Canadian sales tax.

Choose a jurisdiction and enter one Canadian-dollar amount. The tool uses the current general rate for a fully taxable transaction.

Province or territoryChoose the rate to calculate. The tool does not determine the legal place of supply.

HST13% general combined rate

What does your amount represent?

+Before taxAdd the jurisdiction’s general sales taxes.−Tax includedEstimate the subtotal and tax lines.

Amount in Canadian dollars

Use a period or comma for decimals. Enter the subtotal or final total selected above.

The amount stays in this browser and is never uploaded.

One amount. Every Canadian jurisdiction.

Choose a province or territory to see the subtotal, separate tax lines, total tax, and final total.

Ontario HST math

One rate, three useful numbers.

When a supply is fully taxable at Ontario’s general HST rate, the same 13% relationship can add tax to a subtotal or extract it from a final total.

× 0.13

Find the HST

Multiply a before-tax subtotal by 0.13. On C$100.00, the estimated Ontario HST is C$13.00.

× 1.13

Find the tax-included total

Multiply the subtotal by 1.13. C$100.00 before tax becomes C$113.00 after 13% HST.

÷ 1.13

Remove HST from a total

Divide a tax-included total by 1.13. C$113.00 reverses to C$100.00 before tax and C$13.00 HST.

Use the result within its scope

The calculator does the math—not the tax analysis.

This calculator assumes 13% Ontario HST applies to the full amount in Canadian dollars. It does not determine registration, place of supply, taxability, exemptions, zero-rating, point-of-sale rebates, filing treatment, or a customer’s province. Confirm those facts before using the result on an invoice or return.

Canada Revenue AgencyCurrent GST/HST rates and official calculatorOpen the official source Canada Revenue AgencyPlace-of-supply rules for choosing a rateOpen the official source Canada Revenue AgencyWhen to register and start charging taxOpen the official source

Questions behind the number

Five checks before you put 13% on an invoice.

What is the current HST rate in Ontario?

The CRA’s current general rate table lists Ontario at 13% HST. A particular supply can still be zero-rated, exempt, rebated, or governed by a special rule.

How much is Ontario HST on C$100?

For an amount fully taxable at 13%, HST is C$13.00 and the tax-included total is C$113.00.

How do I remove Ontario HST from a tax-included total?

Divide the final total by 1.13 to estimate the before-tax amount, then subtract that subtotal from the total to find the HST. Invoice-level rounding can create a one-cent difference.

Do I always charge 13% because my business is in Ontario?

No. The applicable rate generally depends on place-of-supply rules and the facts of the transaction, not only the seller’s address. Screen the customer and supply facts first.

Does crossing C$30,000 automatically make every sale 13%?

No. Registration timing and the rate or tax treatment of a particular supply are separate questions. Use the Ontario threshold guide and the CRA sources to review both.

From arithmetic to a defensible invoice

Confirm why 13% applies, then preserve the evidence.

Use the Ontario threshold guide for registration timing, screen the service place of supply, and create an invoice only after the tax path is confirmed. The C$19 Action Kit adds a repeatable classification and evidence workflow.

Read the Ontario threshold guide Screen the place of supply Build a GST/HST invoice See the C$19 Action Kit