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Reverse Sales Tax Calculator

Pre-tax price from receipt total
Forward & reverse modes
Any tax rate or VAT
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Reverse Sales Tax Formula: Why $107.50 ÷ 1.075 Gives the Pre-Tax Price and Multiplying by 7.5% Gives the Wrong Answer

Sales tax in the United States is applied to the pre-tax price, not the total. When you see a $107.50 receipt at 7.5% tax, the tax was calculated on the unknown pre-tax price, not on $107.50. To reverse the calculation, you must divide by (1 + rate), not subtract a percentage from the total. Subtracting 7.5% from $107.50 gives $99.44, which is wrong. The correct pre-tax price is $100.00.

Forward: Total = Pre-Tax × (1 + Rate / 100) Reverse: Pre-Tax = Total ÷ (1 + Rate / 100) Tax Amount = Total − Pre-Tax

The table below shows why multiplying the total by the rate overstates the tax for a $107.50 receipt at 7.5%:

MethodCalculationTax AmountPre-Tax Price
Correct: divide by (1 + rate)$107.50 ÷ 1.075$7.50$100.00
Wrong: multiply total by rate$107.50 × 0.075 = $8.06$8.06$99.44

State Sales Tax Rates and Combined Local Rates: Why California's 7.25% Base Becomes 10.25% in Los Angeles and 8.50% in San Diego

The state base rate is only part of what you pay. Every state with a sales tax allows counties and cities to add local rates on top of the state minimum. When you enter the rate from your receipt into this calculator, use the combined rate, not just the state base. The rate printed on your receipt already reflects the combined applicable rate for your purchase location.

StateBase RateCombined Rate Example
California7.25%Los Angeles: 10.25% | San Diego: 8.50%
Texas6.25%Dallas: 8.25% | Houston: 8.25%
New York4.00%New York City: 8.875%
Florida6.00%Miami-Dade: 7.00% | Hillsborough: 8.50%
Illinois6.25%Chicago: 10.25%
Oregon0.00%No sales tax statewide

For online purchases, sellers typically charge the tax rate at the buyer's shipping address, not the seller's location. A California retailer shipping to Texas charges Texas rates. The same reverse formula applies regardless of jurisdiction, divide the total by (1 + combined rate).

Five Reverse Sales Tax Errors That Produce Incorrect Pre-Tax Amounts on Business Expense Reports and Receipts

Subtracting the tax percentage directly from the total
If the total is $107.50 at 7.5%, the tax is NOT $107.50 × 7.5% = $8.06. The tax rate was applied to the pre-tax price, not the total. Always divide by (1 + rate) first to find the pre-tax base, then subtract to get the tax amount.
Using the state base rate instead of the actual receipt rate
Most purchases are subject to state tax plus local taxes. California's state rate is 7.25% but Los Angeles adds a combined city and county rate, making the final rate 10.25%. Always use the rate shown on your actual receipt, not just the state base rate from a tax table.
Assuming all product categories in a state are taxed at the same rate
Many states exempt groceries, prescription drugs, or clothing from sales tax entirely. Some apply reduced rates to certain food items. If your receipt shows a rate lower than the state base rate, the merchant may have applied a partial or full exemption to some line items.
Confusing tax-exclusive (US) and tax-inclusive (VAT) pricing
In the US, price tags are pre-tax (exclusive). In countries using VAT, UK, EU, the displayed price includes the tax. For US receipts, use reverse mode to find the pre-tax amount. For VAT-inclusive foreign invoices, use the same reverse formula with the local VAT rate.
Applying one tax rate to a multi-rate receipt
Sales tax is sometimes applied per line item at different rates, food at 0%, clothing at the state rate, electronics at the combined rate. The total tax on your receipt may not equal the total price × a single rate. For expense reports, use the tax amount printed on the receipt rather than back-calculating from the total.

Frequently Asked Questions

Divide the total (tax-included) price by (1 + tax rate). For example, a $107.50 total at 7.5% tax: $107.50 ÷ 1.075 = $100.00. The tax amount is $107.50 − $100.00 = $7.50. Many people mistakenly subtract the tax percentage from the total directly, that gives the wrong answer because the tax was calculated on the pre-tax price, not the total.

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Sources & References

1
Tax Foundation, State and Local Sales Tax Rates, 2025 ↗, Source for state base sales tax rates, combined state and local averages, and identification of states with no statewide sales tax.
2
Sales Tax Institute, How Sales Tax Is Calculated ↗, Reference for the tax-exclusive pricing model used in the United States, including forward and reverse calculation formulas.
3
OECD, Consumption Tax Trends 2024 (VAT/GST and Sales Taxes) ↗, International reference confirming the reverse calculation formula applies identically to tax-inclusive VAT pricing used in EU and UK markets.
HR
Hassaan Rasheed
Developer and Researcher, CalculatorFlux

Researches and verifies the formulas, methodology, and source data behind each calculator on CalculatorFlux. All tools are built and checked against the cited references before publication.

Last updated: June 2026
State Sales Tax Rates 2025
StateBase Rate
California7.25%
Texas6.25%
New York4.00%
Florida6.00%
Illinois6.25%
Washington6.50%
Nevada6.85%
Tennessee7.00%
Colorado2.90%
OregonNone
MontanaNone
State base rates only. Local taxes add 0–5%.
Pro Tip
  • Always divide by (1 + rate), never subtract the rate from the total
  • Use the combined rate from your receipt, not the state base rate
  • For VAT-inclusive foreign invoices, the same formula applies
  • For expense reports, use the tax amount printed on the receipt
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