Sales Tax Calculator
Calculate the sales tax amount and total price from a pre-tax amount and tax rate, or work in reverse from a total to find the original pre-tax amount.
Pre-tax amount
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Tax amount
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Total
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How It Works
In forward mode, the tax amount is the pre-tax amount multiplied by the tax rate divided by 100. The total is the pre-tax amount plus the tax amount.
In reverse mode, the total you paid already includes tax. The pre-tax amount equals the total divided by (1 + rate/100), and the tax amount is the total minus that pre-tax amount.
Both directions use the same underlying relationship: total = pre-tax × (1 + rate/100). The only difference is which values you already know.
Frequently Asked Questions
When should I use reverse mode?
Use reverse mode when a receipt shows only the total and you want to know how much of it was tax. It backs out the pre-tax price from a tax-inclusive total.
What tax rate should I enter?
Enter the combined state, county, and local sales tax rate that applies to your purchase. You can find the combined rate for your location on your state revenue department website.
Does this work for VAT?
Yes. The math is the same as for sales tax. Use reverse mode with a tax-inclusive price to extract the VAT amount and the pre-tax price.