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Reverse Sales Tax Calculator

Calculate the original pre-tax price from a total amount including sales tax. Select your state for automatic tax rate lookup, or enter any custom rate.

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Reverse Tax Formula: Pre-Tax Price = Total Price ÷ (1 + Tax Rate)

Example: $107.50 at 7.5% tax → $107.50 ÷ 1.075 = $100.00 pre-tax

🧮 Enter Details

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💡 Tip: Check your receipt for the exact tax rate, or use the "By State" tab to look up your state's rate.

📊 Results

Original Price (Before Tax)

$100.00

Sales Tax Amount

$7.50

Total Paid$107.50
Tax Rate7.5%
Pre-Tax Price$100.00
Tax Paid$7.50

✓ Verification: $100.00 + $7.50 = $107.50

🧾 How to Reverse Calculate Sales Tax

Reverse sales tax calculation is the process of determining the original price of an item before sales tax was added, when you only know the total amount paid. This is useful for expense reporting, business accounting, and understanding how much of your purchase went to taxes.

The Reverse Sales Tax Formula

Step-by-Step:

  1. Convert tax rate to decimal: Rate ÷ 100
  2. Add 1 to the decimal: 1 + Rate
  3. Divide total by that number: Total ÷ (1 + Rate)
  4. Subtract to find tax: Total - Pre-Tax = Tax Amount

Example Calculation

You paid $107.50 for an item in a state with 7.5% sales tax:

  • Convert: 7.5 ÷ 100 = 0.075
  • Add 1: 1 + 0.075 = 1.075
  • Divide: $107.50 ÷ 1.075 = $100.00 (pre-tax price)
  • Tax paid: $107.50 - $100.00 = $7.50

When to Use Reverse Sales Tax

This calculation is commonly needed for:

  • Business expense reports — separate tax from purchase price
  • Accounting and bookkeeping — record revenue vs. tax collected
  • Invoice verification — check if vendors charged correct tax
  • Tax deductions — know the actual item cost vs. tax
  • Price comparisons — compare prices across states with different tax rates

📋 Quick Reference

• Formula: Total ÷ (1 + Rate)

• 5% tax → divide by 1.05

• 6% tax → divide by 1.06

• 7% tax → divide by 1.07

• 8% tax → divide by 1.08

• 10% tax → divide by 1.10

🎉 No Sales Tax States

• Alaska*

• Delaware

• Montana

• New Hampshire

• Oregon

*Alaska has no state tax but allows local taxes

Frequently Asked Questions

To reverse calculate sales tax, divide the total price (including tax) by (1 + tax rate as a decimal). For example, if you paid $107.50 and the tax rate is 7.5%, calculate: $107.50 ÷ 1.075 = $100.00. The pre-tax price is $100, and the tax amount is $7.50.

The formula is: Pre-Tax Price = Total Price ÷ (1 + Tax Rate/100). To find the tax amount: Tax Amount = Total Price - Pre-Tax Price. This formula works for any percentage-based tax including sales tax, VAT, and GST.

A reverse sales tax calculator is useful for: expense reporting and reimbursements, business accounting where you need to separate revenue from tax collected, verifying vendor invoices, understanding how much you actually paid for an item vs. tax, and tax deduction purposes.

Five US states have no state-level sales tax: Alaska, Delaware, Montana, New Hampshire, and Oregon. However, Alaska allows local governments to charge sales tax, so some Alaska cities do have local sales taxes. Delaware has no sales tax at all.

Local taxes (county, city, district) are added to the state rate to create a combined rate. When reverse calculating, you must use the total combined rate, not just the state rate. For example, in Los Angeles, the combined rate is about 9.5% (7.25% state + local), not just California's 7.25%.

Yes! The reverse calculation formula works the same for any percentage-based consumption tax. Whether it's US sales tax, European VAT, Canadian GST/HST, or Australian GST, the math is identical: divide the total by (1 + tax rate).

⚠️ Disclaimer: This calculator provides estimates based on state-level sales tax rates only. Actual tax rates may vary with local county, city, and district taxes. Always verify the exact tax rate from your receipt or local tax authority for accurate calculations. This tool is for informational purposes only and should not be used as the sole basis for financial decisions.