Sales Tax Calculator — Add or Remove Tax From Any Price

Total = Price × (1 + Tax% / 100)
Tax Amount = Price × (Tax% / 100)

Reverse (find pre-tax):
Pre-tax = Total / (1 + Tax% / 100)

To remove tax correctly, divide by (1 + rate). Simply subtracting the tax percentage from the total is a common mistake that gives the wrong answer.

Total with tax (price A1, rate% B1)

=A1*(1+B1/100)

Pre-tax from total

=A1/(1+B1/100)

Tax amount only

=A1*(B1/100)

Sales Tax Calculation ExplainedSearch YouTube tutorials →

How Sales Tax Works in the US

Sales tax in the United States is levied at the state and local level, not federally. This creates significant variation across the country — five states have no sales tax at all (Oregon, Montana, New Hampshire, Delaware, and Alaska at the state level), while combined state and local rates in some jurisdictions exceed 10%.

Unlike in most other countries where tax is included in the displayed price, US retailers typically show pre-tax prices and add tax at the register. This is why the sticker price is rarely what you actually pay. Understanding the math helps you budget accurately, especially for larger purchases where tax is a meaningful amount.

The 2018 Supreme Court decision in South Dakota v. Wayfair expanded states' ability to collect sales tax from out-of-state online sellers. Today most major online retailers collect sales tax based on the buyer's location, closing the era where online shopping was often tax-free.

The Correct Way to Remove Tax from a Total

The most common sales tax math error is removing tax by subtracting the tax rate percentage from the total. Example: you paid $108 and the tax rate was 8%. You might try $108 × (1 - 0.08) = $99.36. But the correct pre-tax price is $100.

The error happens because the 8% was calculated on $100, not on $108. To reverse correctly, divide by (1 + rate): $108 / 1.08 = $100. This is what the calculator does in reverse mode. The wrong method will always give you a slightly lower pre-tax number than the actual original price.

Frequently Asked Questions

The national average combined state and local sales tax rate is approximately 7.1%. Rates range from 0% in five no-tax states to over 11% in some Louisiana and Tennessee localities. When budgeting, it's worth looking up your specific city and county rate — many tax agencies publish lookup tools.

Generally yes — sales tax is applied to the final discounted price, not the original. A $100 item discounted to $80 has tax calculated on $80. Some states have specific rules for different promotion types (coupons vs. store discounts vs. manufacturer coupons), but the final selling price is typically the taxable amount.

Most states exempt basic groceries from sales tax as a policy choice to avoid taxing necessities. However, prepared foods, sodas, candy, and alcohol are typically taxed even in states that exempt groceries. The definitions can be surprisingly specific — whether a rotisserie chicken is "prepared food" varies by state.

The most reliable source is your state's department of revenue website, which usually has a lookup tool by zip code. Google also often surfaces the combined rate for a specific city when you search "[city] sales tax rate."