Reverse Tax Calculator

Reverse GST Calculator — Remove GST From a Total 2026

Enter a total that already includes tax and pick the province. You get the price before tax, the GST, and any provincial sales tax.

✓ Free ✓ No Credit Card ✓ All 13 Provinces & Territories

÷ 1.05 GST only

Total

Tax included

1.05

1 + 5% GST

Pre-tax

Price before GST

Quick Answer: to remove 5% GST, divide by 1.05.

$105.00 ÷ 1.05 = $100.00 before tax | GST = $5.00

How do I calculate GST backwards? Divide the tax-included total by 1.05 to get the price before tax; the difference is the GST. Where a provincial tax is also included, divide by 1 plus the combined rate.

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Remove GST From a Total

Enter a tax-included amount and choose the province

Province or territory

Total Amount Including Tax ($CAD)

In an HST province (Ontario, Nova Scotia, New Brunswick, Newfoundland and Labrador, PEI) use the Reverse HST Calculator.

Price before tax $0.00

GST (5%) $0.00

Total entered $0.00

$0.00 ÷ 1.05 = $0.00 pre-tax

Results are estimates. Due to rounding, amounts can differ from final totals by a cent.

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How Reverse GST Works

Receipts often show only the total. These are the formulas behind the calculator, and what to watch for when another tax is included.

The Reverse GST Formula

For a GST-only total: price before tax = total ÷ 1.05, and GST = total − price before tax. The GST is 5/105 of the total, about 4.76%. Do not take 5% of the total: on $105.00 that gives $5.25 instead of the correct $5.00, because the 5% was charged on the price before tax, not on the total.

When Another Tax Is Included

In British Columbia, Saskatchewan, Manitoba, and Quebec a receipt total includes GST and a provincial tax. Divide by 1 plus the combined rate (1.12, 1.11, 1.12, or 1.14975), then apply each rate to the price before tax. The calculator above does this for you and rounds each line to the cent so the lines add up exactly to the total you entered.

Recording GST on Expenses

If you are registered for GST/HST, the GST you paid on business purchases is claimed as an Input Tax Credit on your return. For purchases of $100 or more, keep a receipt showing the supplier's GST/HST number. iBill's expense tracking records the tax on each expense so it is ready at filing time.

Reverse GST Examples (5% GST Only)

For Alberta, Yukon, the Northwest Territories, and Nunavut

Total (tax included)	Price before tax	GST (5%)
$105.00	$100.00	$5.00
$100.00	$95.24	$4.76
$500.00	$476.19	$23.81
$1,000.00	$952.38	$47.62
$2,500.00	$2,380.95	$119.05

Common Reverse GST Questions

What is 5% GST backwards?

Dividing by 1.05. A total of $1,000.00 including 5% GST is $952.38 before tax and $47.62 GST. Multiplying the total by 0.05 ($50.00) is the common mistake.

How much GST is in $100?

If $100.00 already includes 5% GST, the price before tax is $95.24 and the GST is $4.76.

How do I find the GST in a BC receipt?

Divide the total by 1.12. A $100.00 BC receipt is $89.29 before tax, $4.46 GST, and $6.25 PST. Select British Columbia in the calculator above.

Reverse GST FAQs

How do I remove 5% GST from a total?

Divide the total by 1.05 to get the price before tax, then subtract it from the total to get the GST. Example: $105.00 ÷ 1.05 = $100.00 before tax, and $5.00 GST. On $500.00 the price before tax is $476.19 and the GST is $23.81.

How do I find the GST in a total that also includes PST?

Divide by 1 plus the combined rate first, then work out each tax on the price before tax. In British Columbia (5% GST + 7% PST) a $1,000.00 total is $892.86 before tax, $44.64 GST, and $62.50 PST. Dividing by 1.05 alone would overstate the GST.

Where is only GST charged?

Alberta, Yukon, the Northwest Territories, and Nunavut charge the 5% federal GST with no provincial sales tax. British Columbia, Saskatchewan, and Manitoba add a separate provincial tax, Quebec adds QST, and Ontario and the Atlantic provinces charge a single HST.

Why would I need to reverse GST?

To record an expense correctly. Many receipts show only a tax-included total; splitting out the GST tells you the amount you can claim as an Input Tax Credit if you are registered, and the cost to record before tax.

Can I claim the PST back like GST?

No. GST (and HST) paid on business purchases can be claimed as Input Tax Credits by registrants, but the provincial sales taxes in British Columbia, Saskatchewan, and Manitoba are generally not recoverable that way. Quebec QST is recovered separately through input tax refunds with Revenu Québec.

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