Your result will appear here
Fill in the fields and press Calculate.
Sales tax works two ways, and people need both. Sometimes you have a pre-tax price and want the total you’ll actually pay; other times you have a receipt total and need to know how much of it was tax. This calculator does either — enter the amount and rate, pick the direction, and see the tax broken out.
How is it calculated?
Adding tax vs extracting tax
| Mode | You have | Formula |
|---|---|---|
| Add | Pre-tax price | tax = price × rate; total = price + tax |
| Extract | Tax-included total | net = total ÷ (1 + rate); tax = total − net |
The difference matters. Extracting tax is not the same as taking the percentage off the total: on a 108.25 total at 8.25%, the tax is 8.25 (giving a 100 net), not 8.93 (which is 8.25% of 108.25).
Where each mode is used
- Add — shopping and quotes, where prices are shown before tax (common in the US).
- Extract — bookkeeping and expenses, where you have a gross total and must split out the tax component for records or reclaim.
A note on rates
Sales tax rates vary by country, state and even city, and some items are taxed differently or exempt. Enter the exact combined rate that applies to your purchase; the calculator doesn’t assume a jurisdiction.
Worked example
A 100 item at an 8.25% sales tax rate: in add mode the tax is 100 × 0.0825 = 8.25 and the total is 108.25. Reverse it — you have a 108.25 receipt and want the tax in extract mode: the net is 108.25 ÷ 1.0825 = 100.00 and the tax is 8.25. Note that naively taking 8.25% of 108.25 would give 8.93, which is wrong — that’s why the extract formula divides rather than multiplies.
FAQ
How do I add sales tax to a price?+
Multiply the price by the tax rate to get the tax, then add it: a 100 item at 8.25% has 8.25 tax and a 108.25 total. Choose “Add tax” mode and the calculator shows the total and the tax separately.
How do I find the tax in a tax-included total?+
Divide the total by (1 + rate) to get the pre-tax amount, then subtract. For 108.25 at 8.25%: 108.25 ÷ 1.0825 = 100 net, so 8.25 was tax. Use “Extract tax” mode — don’t just take the percentage of the total, which over-states the tax.
Why can’t I just take the percentage off the total to get the tax?+
Because the tax was charged on the smaller pre-tax price, not on the total. 8.25% of the 108.25 total is 8.93, but the actual tax was 8.25. To reverse tax correctly you divide by (1 + rate), which is what extract mode does.
What sales tax rate should I enter?+
The combined rate for your location and item. In the US that’s state plus any county and city rates; elsewhere it may be a national VAT/GST rate. Rates and exemptions vary widely, so use the exact figure that applies rather than a default.
Is sales tax the same as VAT?+
They’re similar in effect but collected differently: US sales tax is added once at the final sale, while VAT/GST is charged at each stage of the supply chain. For a single purchase, this calculator handles both — enter the rate and whether tax is being added or extracted.