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Reverse TaxCalculator
⚡ 100% Free & Client-Side Reverse Calculation Tool

Reverse Tax Calculator

Instantly calculate pre-tax net prices and exact tax paid backwards from any total amount.

Sales Tax Calculator⚡ Instant Calculation
$
%
Calculation Breakdown
Pre-Tax Amount (Net Subtotal)
$0.00
Sales Tax Paid
$0.00
Tax-Included Price (Gross)
$0.00

Select Your State or Region Tax Calculator

Pre-filled with official state & regional tax rates. Click any region to calculate backwards.

AlabamaSales Tax 4%AlaskaSales Tax 0%ArizonaTPT Sales Tax 5.6%ArkansasSales Tax 6.5%CaliforniaSales Tax 7.25%ColoradoSales Tax 2.9%ConnecticutSales Tax 6.35%DelawareGross Receipts Tax 0%District of ColumbiaSales Tax 6%FloridaSales Tax 6%GeorgiaSales Tax 4%HawaiiGET Sales Tax 4%IdahoSales Tax 6%IllinoisSales Tax 6.25%IndianaSales Tax 7%IowaSales Tax 6%KansasSales Tax 6.5%KentuckySales Tax 6%LouisianaSales Tax 4.45%MaineSales Tax 5.5%MarylandSales Tax 6%MassachusettsSales Tax 6.25%MichiganSales Tax 6%MinnesotaSales Tax 6.875%MississippiSales Tax 7%MissouriSales Tax 4.225%MontanaSales Tax 0%NebraskaSales Tax 5.5%NevadaSales Tax 6.85%New HampshireMeals & Rooms Tax 0%New JerseySales Tax 6.625%New MexicoGross Receipts Tax (GRT) 4.875%New YorkSales Tax 4%North CarolinaSales Tax 4.75%North DakotaSales Tax 5%OhioSales Tax 5.75%OklahomaSales Tax 4.5%OregonSales Tax 0%PennsylvaniaSales Tax 6%Rhode IslandSales Tax 7%South CarolinaSales Tax 6%South DakotaSales Tax 4.2%TennesseeSales Tax 7%TexasSales Tax 6.25%UtahSales Tax 6.1%VermontSales Tax 6%VirginiaSales Tax 5.3%WashingtonSales Tax 6.5%West VirginiaSales Tax 6%WisconsinSales Tax 5%WyomingSales Tax 4%

How Reverse Calculation of Tax Works

To perform a reverse calculation of tax from a tax-included total price, divide the total gross amount by 1 + tax rate (in decimal format) to find the pre-tax net price. Subtract the net price from the total to get the exact tax paid. For example, a receipt of $107.00 with 7% sales tax equals a pre-tax price of $100.00 ($107.00 ÷ 1.07) and $7.00 in tax.

Tax rates verified: August 2026Supports US Sales Tax, VAT, GST, HST & Payroll Net-to-Gross

Comprehensive Guide to Reverse Tax Calculation

Managing business accounting, filing personal expense reports, or reviewing commercial receipts frequently requires determining the original pre-tax price of an item when only the tax-inclusive gross total is known. Using a dedicated reverse tax calculator simplifies this process, eliminating mathematical errors and saving valuable time for accountants, small business owners, and consumers alike.

How Reverse Calculation of Tax Works Step-by-Step

A reverse calculation of tax works by isolating the base price before sales tax or VAT was added. While standard forward tax tools multiply a subtotal by $(1 + r)$, reversing the process requires dividing the gross total by $(1 + r)$.

What is a Reverse Tax Calculator?

A tax calculator in reverse is a specialized financial tool designed to extract the base net price and the tax paid from a final transaction total. Standard forward tax calculators take a pre-tax subtotal and add tax to determine the total price. Conversely, an online reverse tax calculator executes a backward mathematical operation to isolate the pre-tax subtotal.

This calculation is vital when handling receipts that display only a single total amount, preparing Value Added Tax (VAT) or Goods and Services Tax (GST) input tax credit claims, or auditing vendor invoices.

The Universal Reverse Sales Tax Formula

The algebraic foundation of a free reverse sales tax calculator relies on understanding how sales tax is originally applied. When sales tax (r) is added to a pre-tax net amount (N), the total gross amount (G) is expressed as:

Gross Amount (G) = Net Amount (N) × (1 + Tax Rate Decimal)
Net Amount (N) = Gross Amount (G) ÷ (1 + Tax Rate Decimal)
Tax Amount = Gross Amount (G) - Net Amount (N)

For a deep dive into formula derivations and mathematical proofs across all tax types, visit our dedicated Reverse Tax Formula & Math Guide.

Why Direct Percentage Subtraction Fails

A common mistake when attempting a manual reverse calculation of tax is subtracting the tax rate percentage directly from the total price. For example, taking 7% off of a $107.00 total yields $107.00 - (107 × 0.07) = $99.51.

This $99.51 result is incorrect because sales tax is legally computed on the lower pre-tax base ($100.00), not the higher post-tax total ($107.00). Taking 7% of $107.00 calculates 7% of a larger number ($7.49), overstating the tax and understating the original price. Dividing by (1 + r) accounts for this base difference perfectly.

Global Tax Implementations Supported

  • US State & Local Sales Tax: California (7.25%), Texas (6.25%), New York (4.0%), Ohio (5.75%), Minnesota (6.875%), Florida (6.0%), plus local city rates up to 10.75%.
  • Canadian Sales Taxes (GST, HST, PST & QST): Alberta (5% GST), Ontario (13% HST), Atlantic provinces (15% HST), British Columbia & Manitoba (12% GST+PST), and Quebec (14.975% GST+QST).
  • European & UK VAT: UK 20% VAT, German 19% MwSt, Spanish 21% IVA, and French 20% TVA.
  • Goods and Services Tax (GST): 10% Australia GST (ATO), 18% India GST, and 9% Singapore GST.

Worked Step-by-Step Examples

US Sales Tax (7% Rate)
Total $107.00 ÷ 1.07 = $100.00 Net | $7.00 Tax
UK VAT (20% Rate)
Total £120.00 ÷ 1.20 = £100.00 Net | £20.00 VAT
Ontario HST (13% Rate)
Total $113.00 ÷ 1.13 = $100.00 Net | $13.00 HST

Frequently Asked Questions

To perform a reverse calculation of tax, divide the total gross amount by 1 plus the tax rate in decimal format. For example, with a $107 total and 7% sales tax rate, divide $107 by 1.07 to get the pre-tax net price of $100.00. The tax amount is $107 minus $100, which equals $7.00.

Popular Regional Calculators

Alabama Calculator
Sales Tax (4%)
Alaska Calculator
Sales Tax (0%)
Arizona Calculator
TPT Sales Tax (5.6%)
Arkansas Calculator
Sales Tax (6.5%)
California Calculator
Sales Tax (7.25%)
Colorado Calculator
Sales Tax (2.9%)