Free Reverse Tax Calculator

Calculate the original amount before tax from the final price. Essential for business expenses, receipt analysis, and tax planning. Works with sales tax, VAT, GST, and any other tax types.

Calculate Pre-Tax Amount

Enter your local sales tax rate (e.g., 7.5 for 7.5%)

Understanding Reverse Tax Calculations

What is a Reverse Tax Calculator?

A reverse tax calculator helps you determine the original amount before tax was applied when you know the final price including tax. This is essential for business expense analysis, receipt verification, and tax planning. Instead of calculating tax forward (amount + tax = total), it works backward (total - tax = amount).

Whether you're dealing with sales tax, VAT, GST, or any other tax type, our calculator provides accurate pre-tax amounts and detailed breakdowns for accounting and business purposes.

Common Use Cases

  • Business expense categorization
  • Receipt analysis and verification
  • Tax return preparation
  • Bookkeeping and accounting
  • Price comparison analysis
  • Invoice reconciliation

How Reverse Tax Calculation Works

Tax-Inclusive Calculation

When you have the final price including tax and need to find the original amount:

Formula: Pre-tax Amount = Total ÷ (1 + Tax Rate)
Example: $107.50 ÷ (1 + 0.075) = $100.00
Most common scenario for business expenses and receipts

Tax-Exclusive Calculation

When you have the pre-tax amount and need to calculate the total with tax:

Formula: Total = Pre-tax Amount × (1 + Tax Rate)
Example: $100.00 × (1 + 0.075) = $107.50
Useful for pricing calculations and quote preparation

Common Tax Rates by Location

United States

  • Delaware: 0% (No sales tax)
  • California: 7.25% - 10.25%
  • New York: 4% - 8.625%
  • Texas: 6.25% - 8.25%
  • Florida: 6% - 8.5%

Canada

  • GST: 5% (Federal)
  • Ontario HST: 13%
  • Quebec: 14.975% (GST + QST)
  • British Columbia: 12% (GST + PST)
  • Alberta: 5% (GST only)

International

  • UK VAT: 20%
  • EU VAT: 17% - 27%
  • Australia GST: 10%
  • New Zealand GST: 15%
  • Japan: 10%

Frequently Asked Questions

When do I need to calculate reverse tax?

You need reverse tax calculation when you have a receipt or invoice showing the total amount including tax, but you need to know the pre-tax amount for accounting, bookkeeping, or tax reporting purposes.

Is this accurate for business use?

Yes, our calculator uses standard mathematical formulas used by accountants and businesses worldwide. However, always verify calculations for important financial decisions and consult with a tax professional for complex situations.

Can I use this for different types of taxes?

Absolutely! This calculator works with any percentage-based tax including sales tax, VAT, GST, HST, and other consumption taxes. Just enter the appropriate tax rate for your location.

What if my receipt shows multiple tax rates?

For multiple tax rates (like GST + PST), add the rates together to get the combined rate. For example, 5% GST + 7% PST = 12% total tax rate.

Need to Calculate Pre-Tax Amounts?

Get accurate tax breakdowns for business expenses and receipts - completely free!

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