Quebec Reverse Tax Calculator
Estimate the pre-tax price and included GST/QST amount for Quebec tax-inclusive prices.
Interactive calculator
Calculate tax backwards
$100.00 at 14.975% GST/QST: pre-tax $86.98, GST/QST $13.02.
Estimate only. Verify official rates before filing, invoicing, or making tax decisions.
Primary query
quebec reverse tax calculator
Default rate
14.975%
Rate source
Revenu Quebec basic GST/QST rulesLast updated
2026-05-14
Formula
How reverse tax calculation works
Start with the tax-inclusive total, then divide by 1 plus the tax rate. Use the tax rate as a decimal in the formula.
Pre-tax Price = Total Price / (1 + Tax Rate)
Tax Amount = Total Price - Pre-tax Price
Example
$100.00 CAD with 14.975% GST/QST
- Tax multiplier = 1.14975
- Pre-tax price = 100 / 1.14975 = 86.98
- Estimated GST/QST amount = 13.02
Region
Quebec tax context
Country
Canada
Tax system
GST + QST
Reference rate
14.975%
Quebec commonly combines federal GST and Quebec QST for tax-inclusive estimates. Always verify the rate for the exact product, location, and filing period before making tax decisions.
Rate breakdown
Estimated split for $100.00.
- Federal GST5% reference rate
- 5% / $4.35
- Quebec QSTQST is calculated on the selling price excluding GST.
- 9.975% / $8.68
Source checked 2026-05-14: Revenu Quebec basic GST/QST rules. Common taxable supplies in Quebec use 5% GST plus 9.975% QST. Some supplies can be exempt or zero-rated.
FAQ
quebec reverse tax calculator questions
How do you reverse calculate tax?
Divide the tax-inclusive total by 1 plus the tax rate. For example, with a 20% tax rate, divide the total by 1.20.
What is the reverse tax formula?
Pre-tax price = total price / (1 + tax rate). Tax amount = total price - pre-tax price.
Is this calculator tax advice?
No. This is an educational calculator for estimates. Confirm official rates and rules before filing, invoicing, or making compliance decisions.
What Quebec tax rate does this calculator use?
It defaults to 14.975% as a combined GST/QST reference rate for common estimates.
Does Quebec QST apply on top of GST?
For the current common calculation, QST is calculated on the selling price excluding GST. This page treats 5% GST plus 9.975% QST as a combined 14.975% reference rate.
Can some Quebec items use a different tax treatment?
Yes. Some supplies can be exempt, zero-rated, or treated differently. Use the rate that applies to the item and verify with Revenu Quebec for compliance decisions.
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