Use this free reverse sales tax calculator to remove tax from a total price and find the price before tax in seconds. Enter the total you paid, including tax, and the tax rate, and the reverse sales tax calculator shows the pre-tax price and the tax amount instantly — no sign-up, no account, and no personal information needed. Your numbers are calculated in your browser and are not sent to us.
Contents: Formula · How to use · Examples · Tips · FAQ · Related tools
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No sign-up required. This reverse sales tax calculator works in your browser, so the total and tax rate you enter are not stored or sent to us. The result is an estimate for general planning, not financial advice.
Reverse Sales Tax Calculator Formula
The reverse sales tax calculator works backwards from a price that already includes tax. A total price is the pre-tax price plus the tax on it, so dividing the total by one plus the tax rate gives the original price before tax.
Pre-tax price = Total price ÷ (1 + Tax rate ÷ 100)
Tax amount = Total price − Pre-tax price
For example, a total of $108 with an 8% tax rate gives a pre-tax price of $108 ÷ 1.08 = $100, and a tax amount of $108 − $100 = $8. The same reverse sales tax calculator formula works for sales tax in the United States, VAT in the United Kingdom, and GST or HST in Canada, because in each case the tax is a percentage added to the pre-tax price. The result is shown in the currency you entered, whether dollars, pounds, or Canadian dollars.
How to Use the Reverse Sales Tax Calculator
Type the total price you paid, including tax, into the first box. Type the tax rate as a percentage into the second box — for an 8% tax rate, type 8, not 0.08. Tap Calculate Pre-Tax Price to see the price before tax and the tax amount at once. If you are checking a receipt, the tax rate is usually printed on it; if it is not, you can find it from the seller or from a published tax rate table for your state, province, or country.
A common mistake is to subtract the tax percentage directly from the total, for example taking 8% off $108 to get $99.36. That is wrong, because the tax was calculated on the $100 pre-tax price, not on the $108 total. Always divide by one plus the rate, as the reverse sales tax calculator does, to get the correct pre-tax price.
Reverse Sales Tax Calculator Examples
Example 1 — $108 total at 8% tax. Pre-tax price = $108 ÷ 1.08 = $100.00. Tax amount = $108 − $100 = $8.00.
Example 2 — $120 total at 20% VAT. Pre-tax price = $120 ÷ 1.20 = $100.00. Tax amount = $120 − $100 = $20.00. This is the standard UK VAT example, and it shows why removing 20% from $120 does not give $96 — the VAT was charged on $100.
Example 3 — $54.50 total at 9% tax. Pre-tax price = $54.50 ÷ 1.09 = $50.00. Tax amount = $54.50 − $50.00 = $4.50.
These reverse sales tax calculator examples are useful for business owners who need the net price for bookkeeping, and for shoppers who want to compare prices before tax across different stores or countries.
Reverse Sales Tax Calculator Tips
Check whether the total really includes tax before you use the reverse sales tax calculator. In the United States, shelf prices often exclude sales tax, so the price at the till is higher than the shelf price, and the receipt total is the tax-inclusive figure to enter. In the United Kingdom, prices shown to shoppers usually already include VAT. Tax rates vary by place, so for United States rates you can check the Tax Foundation's state sales tax rates. If a price was also discounted, first use the discount calculator to check the sale price, then use this tool on the discounted total if tax was charged on it.
Reverse Sales Tax Calculator FAQ
What does a reverse sales tax calculator do? A reverse sales tax calculator takes a total price that includes tax and works out the price before tax and the amount of tax paid. It reverses the usual tax calculation.
How do I remove sales tax from a price? Divide the total price by one plus the tax rate as a decimal. For a $108 total at 8%, divide $108 by 1.08 to get $100 before tax.
Can I use it for VAT? Yes. VAT is a percentage tax added to a net price, so the same reverse sales tax calculator formula works for VAT, GST, and HST as well as sales tax.
What if I do not know the tax rate? Check your receipt, ask the seller, or look up the published rate for your state, province, or country. Without the rate, the pre-tax price cannot be separated from the total.
Why does my result differ from my receipt by a cent or two?e Receipts round tax on each line, so dividing a rounded total can differ by a cent or two. A small difference like that is rounding, not an errorin the formula./p>
What is the difference between this and a normal sales tax calculator? A normal sales tax calculator adds tax to a net price, while a reverse sales tax calculator removes tax from a total price. Use this tool when you already know the final amount paid.
Related Tools
Try the Discount Calculator to find a sale price, the Percentage Increase Calculator to measure a price change, the Home Loan Calculator for monthly loan payments, and the Compound Interest Calculator to see how savings grow over time. Return to the PDGPT homepage to browse all free calculators by category.
Sources and Method
This calculator uses the formulas Pre-tax price = Total price / (1 + Tax rate / 100); Tax amount = Total price - Pre-tax price. For United States rates, see the Tax Foundation's state sales tax rates. Results are estimates for general planning, not tax or financial advice. Last updated: October 28, 2026.