Enter your total price (including tax) and sales tax rate to work backwards and find the original pre-tax price and the exact tax amount paid. The Reverse Sales Tax Calculator uses the formula Original Price = Final Price ÷ (1 + Tax Rate/100) — useful for accounting, expense reports, or verifying receipts.
Original Price (Before Tax)
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Tax Amount
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Final Price (With Tax)
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Tax as % of Total
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A reverse sales tax calculator works backwards from a total price (including tax) to find the original pre-tax price and the tax amount. Instead of adding tax to a base price, it subtracts the tax component from the final amount. It's useful for accounting, expense tracking, and verifying receipts.
Divide the total price by (1 + tax rate/100) to get the original pre-tax price. Then subtract the original price from the total to find the tax amount. For example, if you paid $107.25 at a 7.25% tax rate: $107.25 ÷ 1.0725 = $100.00 original price, and $107.25 − $100.00 = $7.25 tax paid.
Common reasons include breaking down receipts for business expense reports, calculating taxable vs. non-taxable portions of a purchase, reconciling accounting records, or verifying that the correct tax was charged on an invoice. It's especially handy when you only have the total charge.
A forward (standard) sales tax calculation starts with the pre-tax price and adds tax to find the total. A reverse calculation starts with the total and works backwards to find the pre-tax price and tax amount. Both use the same underlying relationship between price, tax rate, and total.
Yes. Sales tax applies to many services depending on the jurisdiction. The reverse calculation method works the same way regardless of whether the purchase was a physical product or a taxable service — as long as you know the total paid and the applicable tax rate.
Sales tax rates can change as frequently as quarterly in some jurisdictions, particularly at the local level. State rates tend to be more stable, but combined state and local rates fluctuate. Always verify the current rate for your specific location before relying on a calculation for official purposes.
You can find your combined state and local sales tax rate by checking your state's Department of Revenue website, looking at a recent receipt from your area, or using a tax rate lookup tool. Rates vary by state, county, and city, so using the correct combined rate is important for accuracy.
Yes. Many jurisdictions exempt certain categories such as groceries, prescription medications, clothing, or agricultural supplies from sales tax. If part of your purchase was exempt, you should only apply the reverse calculation to the taxable portion of the total to get accurate results.