Reverse Tax Calculator
Enter a total price with tax included and a tax rate. The calculator instantly backs out the pre-tax price and the tax amount.
Interactive calculator
Calculate tax backwards
$120.00 at 20% Tax: pre-tax $100.00, Tax $20.00.
Estimate only. Verify official rates before filing, invoicing, or making tax decisions.
Primary query
reverse tax calculator
Default rate
20%
Rate source
Manual rate input
Last updated
2026-05-14
Formula
How reverse tax calculation works
Start with the tax-inclusive total, then divide by 1 plus the tax rate. Use the tax rate as a decimal in the formula.
Pre-tax Price = Total Price / (1 + Tax Rate)
Tax Amount = Total Price - Pre-tax Price
Example
$120.00 with 20% tax
- Tax multiplier = 1 + 20% = 1.20
- Pre-tax price = 120 / 1.20 = 100.00
- Tax amount = 120.00 - 100.00 = 20.00
FAQ
reverse tax calculator questions
How do you reverse calculate tax?
Divide the tax-inclusive total by 1 plus the tax rate. For example, with a 20% tax rate, divide the total by 1.20.
What is the reverse tax formula?
Pre-tax price = total price / (1 + tax rate). Tax amount = total price - pre-tax price.
Is this calculator tax advice?
No. This is an educational calculator for estimates. Confirm official rates and rules before filing, invoicing, or making compliance decisions.
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