Tallyloom

Sales Tax Calculator

Add sales tax to a price, or back the tax out of a receipt total — both directions, any rate, with the formula shown.

total = price × (1 + rate)
Total with tax
$107.00
Tax: $7.00 · on $100.00

How to use this tool

  1. Pick a direction: add tax to a price, or extract tax from a total.
  2. Enter the amount and your combined state + local tax rate.
  3. Read the result — price, tax, and total are all shown.

How it works

Adding tax: total = price × (1 + rate). Backing tax out of a receipt total is the one people get wrong: pre-tax price = total ÷ (1 + rate) — not total × (1 − rate), which undershoots. US sales tax combines state and local rates, so use the rate for the place of purchase. Informational only — rates and taxability rules vary by jurisdiction and product; this is not tax advice.

Sources & references

Content last reviewed: July 2026.

Frequently asked questions

How do I find the pre-tax price from a total?

Divide by 1 plus the rate. A $107 total at 7% tax is $107 ÷ 1.07 = $100 pre-tax, $7 tax. Subtracting 7% of the total gives the wrong answer.

What sales tax rate should I use?

The combined state + county + city rate where the purchase happens. In the US these range from 0% (a few states) to over 10% combined; check your state's revenue department or the receipt itself.

Does this handle VAT?

The math is identical — VAT-inclusive pricing is the 'extract from total' mode. Enter the VAT rate and the tax-inclusive price.