Sales Tax Calculator
Add tax to a price, or run it backwards: give it a receipt total and it tells you how much of it was tax. Works with any rate — US state and local sales tax, VAT or GST.
Your numbers
Result
- Price before tax
- $100.00
| Item | Amount |
|---|---|
| Price before tax | $100.00 |
| Sales tax (8.25%) | $8.25 |
| Total with tax | $108.25 |
Adding tax to a price
Straightforward: tax = price × rate, and total = price + tax. A $100 item at 8.25% carries $8.25 of tax and rings up at $108.25.
Working backwards from the total
This is the one people get wrong. If a receipt says $108.25 including 8.25% tax, you cannot just take 8.25% of $108.25 — that gives $8.93, which is too much. The tax was charged on the pre-tax price, not the total.
The right move is to divide:
price before tax = total ÷ (1 + rate)
So 108.25 ÷ 1.0825 = 100.00, and the tax was $8.25. Switch the mode field to run it this way.
Which rate should you use?
Whichever applies to you — that is why this calculator does not ship a rate table. In the US, sales tax is set by state and often stacked with county and city rates, so two shops a few miles apart can charge differently; five states charge no state sales tax at all. VAT and GST rates are national. Check your local rate and enter it.
Frequently asked questions
Sources
- Tax Foundation — State and local sales tax rates
- OECD — Consumption tax trends (VAT/GST rates)