Sales Tax Calculator

Sales tax formulas

• Adding tax: tax = price × rate ÷ 100, and total = price + tax.
• Removing tax: price before tax = total ÷ (1 + rate ÷ 100), and tax = total − price before tax.

The second formula is the one people most often get wrong. Subtracting the rate from the total (for example taking 8.25% off 108.25) gives the wrong answer, because the tax was charged on the smaller pre-tax price, not on the total.

Worked examples

Adding tax. A price of 80.00 with 8.25% sales tax: tax = 80 × 0.0825 = 6.60, so the total is 86.60.

Removing tax. A receipt total of 108.25 includes 8.25% tax: price before tax = 108.25 ÷ 1.0825 = 100.00, and the tax is 8.25. If you had instead taken 8.25% of 108.25 you would have got 8.93, which is wrong.

How to use the calculator

1. Enter the amount and the sales tax rate for your area.
2. Choose whether to add tax to the amount or remove tax from it.
3. Press Run to see the price before tax, the sales tax and the price with tax.

Quick mental math

To estimate tax at a whole-percent rate, find 1% (move the decimal two places) and multiply. For 8% on 60: 1% is 0.60, so 8% is 4.80. Or take 10% (6.00) and subtract 2% (1.20) to get the same 4.80. At 7%, the tax on 50, 100 and 250 is 3.50, 7.00 and 17.50.

Working backwards, divide the total by 1 plus the rate. At 10%, a total of 55 means a pre-tax price of 55 ÷ 1.10 = 50.00 and tax of 5.00.

Sales tax, VAT and GST

Sales tax is added at the point of sale in the United States and is usually shown separately on the receipt. VAT and GST are charged at each stage of the supply chain and are often already included in shop prices in many countries. The arithmetic for adding or removing the percentage is identical, so this calculator works for all three.

Things to keep in mind

• Sales tax rates differ by state, county and city, and some items (such as groceries or clothing) can be taxed differently or not at all. Use the rate printed on your receipt or published by your local tax authority.
• The calculator applies one rate to the whole amount. If a purchase mixes taxable and non-taxable items, calculate them separately.
• Store systems round tax per item or per receipt, so a total can differ by a cent from your calculation.
• The tool does only arithmetic, so the amount can be in any currency, and it also works for VAT or GST if you enter that rate.

Frequently asked questions

How do I find the price before tax?

Choose 'Remove tax from a price that includes it', enter the total and the rate. The calculator divides the total by 1 plus the rate.

Why not just subtract the tax percentage from the total?

Because the tax was calculated on the pre-tax price. For a total of 108.25 at 8.25%, the correct pre-tax price is 100.00, while subtracting 8.25% of the total gives 99.32.

Does the calculator know my local rate?

No. You enter the rate yourself, so it works for any state, country or tax type.

Can I use it for VAT or GST?

Yes. It applies a percentage in the same way, so enter your VAT or GST rate.

Is my data stored?

No. The calculation runs in your browser.