Reverse Sales Tax Calculator
Enter a total price that already includes sales tax, and the tax rate. The calculator works backward to show the price before tax and the amount of tax in it.
How to use this Reverse Sales Tax Calculator
- Enter the total you paid, including tax.
- Enter the sales tax rate that applied, as a percentage.
- Add the quantity if you want a price per item.
- Press Calculate to see the price before tax.
- Use Copy result to share the figures.
How to calculate the price before sales tax
A total with tax is the price before tax times one plus the tax rate. Work backward by dividing.
- Price before tax = total / (1 + rate)
- Tax = total – price before tax
Worked example
A receipt shows a total of $107.25, and the sales tax rate is 7.25%. The price before tax is 107.25 / 1.0725 = $100.00. The tax is $7.25. If you only subtract 7.25% from the total, you get $99.47, which is wrong, because the tax was added to the smaller price and not to the total.
This is a common mistake when you work backward by hand. Always divide by one plus the rate. The calculation is useful when a receipt shows only the total, when a business enters sales that include tax into its books, or when you need to work out how much tax to report. For a business that sells at tax-inclusive prices, the amount of tax in a sale is the total minus the price before tax. Tax rules differ by place and by item, and some items are not taxed at all, so check what applies to you or ask a tax professional. For example, a bill of $53.63 at a 7.25% rate comes to a price of $50.00 before tax, with $3.63 of tax. The same approach works for a rate of any size, so you can use it for city, county or state rates. If a receipt lists the tax on a separate line, use that figure and the pre-tax subtotal to check your result.
Assumptions & limits
- The tax rate is an input. Sales tax rates vary by state, county and city and they change. This calculator does not look them up.
- The calculation assumes one rate applies to the whole total. Mixed baskets with taxed and untaxed items need to be split.
- Rounding on a receipt can differ by a cent from the exact result.
- It does not cover VAT or other taxes that work differently.
- It is a calculation tool and not tax advice.
Frequently asked questions
How do I find the price before sales tax?
Divide the total by one plus the tax rate. $107.25 at 7.25% gives $100.00.
Why not just subtract the tax percentage?
Because the tax was added to the price before tax, not to the total, so a straight subtraction gives the wrong answer.
How do I find the tax amount?
Subtract the price before tax from the total.
Where do I find my sales tax rate?
Check your state and local tax authority, or the receipt.
Does it work for VAT?
The same math applies for a flat rate that is added on top, but check your local rules.
Can I use it for several items?
Yes, if the same rate applies. Enter the quantity for a per-item price.
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Last updated: November 2026