Sales Tax Calculator

Add sales tax to a pre-tax price, or work backward from a tax-included total to find the original price and tax amount.

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Adding tax vs. removing tax

Adding tax multiplies the pre-tax price by (1 + tax rate). Removing tax from a total does the opposite: dividing the total by (1 + tax rate) to back out the original pre-tax price — you can't just subtract the tax rate percentage directly from the total, since the tax rate applies to the smaller pre-tax amount, not the total.

Frequently asked questions

Why can't I just subtract the tax percentage from my total to find the pre-tax price? Because the tax was calculated as a percentage of the smaller pre-tax price, not the total — subtracting the percentage from the total overcorrects. Dividing by (1 + rate) is the mathematically correct way to reverse it.

Do sales tax rates vary by location? Yes — in the U.S. they vary by state, county, and city, and combined local rates can differ significantly even within the same state. Check your specific jurisdiction's combined rate for accuracy.

Are all goods and services taxed at the same rate? No — many jurisdictions exempt or apply reduced rates to items like groceries, prescription medication, or clothing, so the "sales tax rate" itself can vary by what you're buying.