GST & PST Backout Calculator (Canada)

Enter a total amount (tax included) and quickly calculate the original pre-tax value, along with GST and PST portions.

This assumes GST and PST apply to the full amount. Some receipts may differ due to mixed tax rules or exemptions.

What Is Tax Backout?

Tax backout means removing GST and/or PST from a total price to find the original pre-tax amount.

When You Need This

Reviewing receipts
Verifying invoices
Accounting and bookkeeping
Separating revenue from collected tax

How It Works

If a total includes tax, you divide by (1 + tax rate) to get the original amount.

Pre-tax = Total ÷ (1 + tax rate)

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Example

If your total is $112 with GST (5%) and PST (7%):

Combined tax = 12%
Pre-tax ≈ $100
GST ≈ $5
PST ≈ $7

Disclaimer

This calculator is provided for informational and educational purposes only. It does not constitute financial, legal, tax, or business advice.

While reasonable efforts have been made to ensure accuracy, results are estimates based on the information you provide. Actual business performance may vary. You should consult a qualified professional before making financial decisions.

All calculations are performed locally in your browser. No data entered into this calculator is transmitted to our servers, stored, or saved. Your inputs remain private to your device.