Enter a tax-included total to find the price before tax and the included tax amounts. Select the province of supply and confirm which taxes were charged. The calculator starts with a $1,130 Ontario receipt: $1,000 before tax and $130 HST.
Reverse a tax-included total
This calculator needs JavaScript. The rules it uses are on the CRA pages linked below.
The province selector changes the available taxes. For BC, Manitoba and Saskatchewan, select provincial tax only when PST or RST applied. For Quebec, select QST when the price includes it. The tool does not decide whether an item is exempt.
The reverse-tax formula
Price before tax = tax-included total ÷ (1 + combined applicable rate).
Included tax = total − unrounded price before tax. To split separate taxes, multiply the unrounded base by each applicable rate, then round the monetary components.
| Taxes included | Divisor | Example total | Price before tax |
|---|---|---|---|
| 5% GST | 1.05 | $1,050.00 | $1,000.00 |
| Ontario 13% HST | 1.13 | $1,130.00 | $1,000.00 |
| Nova Scotia 14% HST | 1.14 | $1,140.00 | $1,000.00 |
| 15% HST | 1.15 | $1,150.00 | $1,000.00 |
| 5% GST + 7% PST/RST | 1.12 | $1,120.00 | $1,000.00 |
| 5% GST + 6% PST | 1.11 | $1,110.00 | $1,000.00 |
| 5% GST + 9.975% QST | 1.14975 | $1,149.75 | $1,000.00 |
These are standard-rate examples, not taxability decisions. CRA’s guidance explains the GST/HST rate and separate PST base; Revenu Québec explains GST/QST arithmetic.
How do I find the original price before GST?
For a total containing only 5% GST, divide by 1.05. A $105 receipt contains a $100 base and $5 GST. Multiplying $105 by 5% gives $5.25, which is not the tax included in that receipt. The equivalent tax-extraction fraction is 5/105 of the total.
Check rounding and mixed-rate purchases
Reverse calculations begin with a total that may already be rounded. The exact reconstructed components can differ by a cent from the supplier’s original lines. A basket containing taxable, zero-rated and exempt items cannot generally be split correctly using one divisor on the entire receipt. Separate the relevant subtotals or obtain an itemized invoice.
Can I claim the extracted tax as an ITC?
Arithmetic does not establish eligibility. A GST/HST registrant needs an eligible commercial purchase, tax that meets the applicable rules, and supporting information. Use the actual invoice and CRA’s ITC requirements; do not create a tax credit solely by applying a reverse formula to a bank payment.
To add tax to a new price instead, use the main GST/HST calculator.