Ecommerce

Sales Tax Calculator

Add sales tax to a price, remove tax from a total, or find the tax rate between any two amounts.

Enter values above to calculate sales tax.

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Sales Tax Formulas

Add Tax

Total = Price × (1 + Rate / 100)

Remove Tax

Pre-tax = Total / (1 + Rate / 100)

Find Rate

Rate = (Total − Pre-tax) / Pre-tax × 100

What is sales tax?

Sales tax is a consumption tax imposed by governments on the sale of goods and services. It is collected by the seller at the point of sale and remitted to the relevant tax authority. In the US, sales tax rates are set at the state and local level, meaning they vary significantly depending on where a transaction takes place.

For e-commerce sellers, understanding sales tax calculations is essential for correct pricing, checkout configuration, and tax remittance. This calculator handles all three common scenarios — adding tax to a price, removing it from a total, or finding the rate — so you can work with any two known values to find the third.

Frequently asked questions

How do I add sales tax to a price?
Multiply the pre-tax price by the tax rate expressed as a decimal and add the result to the original price. For example, a $100 item with 8% sales tax: $100 × 0.08 = $8 tax, so the total is $108. This calculator handles that math instantly when you enter the price and rate.
How do I remove sales tax from a total?
Divide the total price by (1 + tax rate / 100) to find the pre-tax amount. For example, a $108 total with 8% tax: $108 / 1.08 = $100 pre-tax, and the tax amount is $8. This is useful when a price tag already includes tax and you need the base price.
How do I find the sales tax rate from two prices?
Subtract the pre-tax price from the total price to get the tax amount, then divide by the pre-tax price and multiply by 100. For example, if the pre-tax price is $100 and the total is $108, the rate is ($108 − $100) / $100 × 100 = 8%.
What is the average US sales tax rate?
As of 2024, combined state and local sales tax rates in the United States average around 7–8%. Rates vary widely by state: some states like Oregon and Montana have no sales tax, while others like Louisiana and Tennessee can exceed 10% when local taxes are included.
Is sales tax the same as VAT?
Both are consumption taxes but they work differently. Sales tax is collected only at the final point of sale (the consumer pays it). VAT (Value Added Tax) is collected at every stage of the supply chain, with each business remitting only the tax on the value it adds. VAT is common in Europe; sales tax is typical in the US.
Do online purchases require sales tax?
In the United States, following the 2018 South Dakota v. Wayfair Supreme Court ruling, states can require out-of-state online retailers to collect sales tax if they exceed certain sales thresholds. Most major e-commerce platforms now collect and remit sales tax automatically.

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