Free reverse sales-tax tool
Sales Tax Backout Calculator
Start with a total that already includes sales tax and calculate the original pretax price, the tax contained in the total, and the per-unit amounts.
Simple calculator
Updates liveBack tax out of the total
Tax-inclusive sale
Reverse-tax formulaPretax price = tax-inclusive total ÷ (1 + tax rate). Sales tax contained in the total = tax-inclusive total − pretax price.
Advanced calculator
Stacked ratesBuild the combined sales-tax rate
Tax-inclusive total
Sales-tax components
Optional target-price check
Partial-taxability modelWhen only part of the pretax sale is taxable, total = pretax subtotal × (1 + combined rate × taxable share). The calculator solves that equation backward from the tax-inclusive total.
Tax bridge
Current assumptionsFrom tax-inclusive total back to pretax price
| Step | Calculation | Amount |
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Rate sensitivity
Same tax-inclusive totalBacked-out price at different combined sales-tax rates
| Combined tax rate | Pretax subtotal | Tax contained in total | Tax share of total paid | Pretax / unit |
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Taxability sensitivity
Combined rate held constantEffect of partially taxable sales
| Taxable share | Pretax subtotal | Taxable pretax amount | Tax contained | Effective tax vs pretax sale |
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Scope
Use the actual rate and taxability rules for the transaction
This calculator performs the arithmetic for backing percentage-based sales tax out of a tax-inclusive amount. It does not determine whether a product or service is taxable, which jurisdiction applies, whether a local cap or bracket applies, marketplace-facilitator treatment, exemptions, tax holidays, special excise taxes, destination sourcing, or filing requirements. Enter the combined rate and taxable share that apply to the transaction.