Free tool
Sales tax calculator (and VAT)
Use this free sales tax calculator to add tax to a price or strip it out of a tax-inclusive total. Works for US sales tax, VAT and GST, with exact cents.
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Result
Calculated in your browser. Nothing is sent anywhere.
Read the full guide: how to use it, what to include, worked example
A sales tax calculator works out the tax on a price, and the total with tax included, in one step. It also works backward: give it a tax-inclusive total and it separates the net price from the tax. The calculator above handles both directions, supports any rate, and is prefilled with an example. It runs in your browser, and nothing you type is uploaded.
How to use the calculator
- Choose a direction. “Add tax” starts from a net price. “Remove tax” starts from a total that already includes tax.
- Enter the amount. Type the price or the tax-inclusive total.
- Enter the rate. Use the percentage that applies to the item and location, such as 8.25.
- Read the result. You get the net amount, the tax amount and the total, each rounded to the cent.
If you want tax applied across several line items on a real document, the free invoice generator uses the same exact money math and adds tax to the invoice for you.
How the math works
Adding tax is a multiplication. The tax is the net price times the rate, and the total is the net price plus the tax.
Removing tax is a division. A tax-inclusive total is the net price times (1 plus the rate). So the net price is the total divided by (1 plus the rate), and the tax is whatever is left.
Rounding matters because money has two decimal places. The calculator rounds half away from zero: an exact half cent goes up for positive amounts and further from zero for negative ones, such as refunds. It rounds the tax amount once, then derives the total from rounded values, so the lines always add up on screen.
Worked examples
| Direction | Input | Rate | Net | Tax | Total |
|---|---|---|---|---|---|
| Add tax | $100.00 net | 8.25% | $100.00 | $8.25 | $108.25 |
| Remove tax | $122.00 total | 22% | $100.00 | $22.00 | $122.00 |
Sales tax and VAT: what is the same, what is not
Both are percentages added to a price, so the calculator treats them the same way. The differences are about who collects and how.
- Sales tax is generally charged once, at the final sale to the customer. In the United States it is set by states and local governments, so rates and rules differ from one place to the next.
- VAT (value-added tax) is charged at each stage of a supply chain, and businesses usually recover the VAT they pay on purchases. Many countries use it, often with several rates for different goods.
- GST is a similar tax in other countries.
For definitions, see the glossary pages on sales tax and VAT.
Common mistakes
- Taking the percentage off the total. To remove tax, divide by 1 plus the rate. Multiplying the total by the rate gives the wrong answer.
- Using one rate everywhere. Rates vary by place and product. Some items are exempt or taxed at a reduced rate.
- Rounding too early. Keep full precision until the final tax amount, then round once to the cent.
- Taxing the wrong base. Check whether shipping, discounts and deposits are part of the taxable amount in your jurisdiction.
- Forgetting to show the tax separately. Invoices usually show the tax as its own line so the client can see the net price, rate and tax.
- Mixing up inclusive and exclusive prices. Retail prices in some countries include VAT. B2B quotes often exclude it. Say which one you mean.
Putting tax on an invoice
A clear invoice lists the net amounts, the tax rate and the tax amount on a separate line, then the total. If you do business in a country with VAT, you may also need to show your tax registration number and follow specific wording rules. The guide on how to add sales tax to an invoice walks through the steps.