Tax-Inclusive Price Breakdown Calculator
Sometimes you only have the final number: a receipt total, a quoted price that already includes tax, or a gross figure you need to split for bookkeeping. This calculator works backward from that tax-inclusive total to recover the two pieces it contains, the pre-tax price and the tax itself. You enter the total and the tax rate that was applied, and it returns the base price and the tax amount. The method matters here, because the common mistake of subtracting the percentage from the total removes too much. Tax was charged on the smaller base price, not on the larger total, so the correct step is to divide the total by one plus the rate expressed as a decimal. That exactly reverses the original multiplication and gives back the base price, and the tax is then simply the total minus that base. The rate field is fully editable so you can use the combined state and local rate that applied where the item was sold, and the same approach works for value added tax or goods and services tax in other systems. Every figure here is computed deterministically from your two inputs, and the worked example below reconciles exactly to the calculator.
To back out tax, divide the total by one plus the rate: pre-tax price = total / (1 + rate), tax = total minus that price. A $107.25 total at 7.25% splits into a $100.00 price and $7.25 in tax.
Tax-inclusive price formula
base = T / (1 + r)
tax = T - base
T = total including tax
r = tax rate as a decimal
Dividing by one plus the rate reverses the multiplication that added the tax in the first place, returning the base price. Subtracting that base from the total leaves the tax.
Worked example
A receipt shows a total of 107.25 dollars and the sales tax rate was 7.25 percent.
- Convert the rate: 7.25% = 0.0725, so 1 + r = 1.0725
- Base price: 107.25 / 1.0725 = 100.00
- Tax: 107.25 - 100.00 = 7.25
The price before tax is 100.00 and the tax is 7.25. These are the calculator's default inputs, so the result above matches the widget exactly.
Backing out tax at common rates
Pre-tax price recovered from a 100 dollar tax-inclusive total.
| Rate | Pre-tax price | Tax |
|---|---|---|
| 5% | $95.24 | $4.76 |
| 7.25% | $93.24 | $6.76 |
| 9% | $91.74 | $8.26 |
| 10% | $90.91 | $9.09 |
Sales and use tax is set by state and local governments: US Internal Revenue Service (IRS).
Tax-inclusive price calculator: frequently asked questions
How do I find the price before tax from a tax-inclusive total?
Divide the total by one plus the tax rate written as a decimal. The pre-tax price equals total divided by (1 plus rate), and the tax is the total minus that price. A 107.25 total at 7.25 percent gives a 100.00 pre-tax price and 7.25 in tax.
Why divide instead of just subtracting the percentage?
Because the tax was applied to the smaller pre-tax price, not to the larger total. Subtracting the rate from the total would remove too much. Dividing by one plus the rate correctly reverses the original multiplication and recovers the exact base price.
When do I need to back out tax from a total?
Common cases include reconciling a receipt that only shows the gross amount, separating tax for bookkeeping or expense claims, and comparing a tax-inclusive quoted price against a pre-tax one. The split lets you record the net price and the tax portion separately.
What rate should I use?
Use the same combined rate that was applied when the item was sold, the state and local sales tax rate for that location. If you are unsure of the exact rate, the receipt total alone cannot tell you the split, so confirm the rate first. The field is editable.
Does this work for VAT or GST too?
Yes. The same divide-by-one-plus-the-rate method backs out any single tax that was added on top of a base price, including value added tax and goods and services tax. Enter the inclusive total and the applicable rate to get the base amount and the tax.
Official sources
- Federal tax administration and taxpayer guidance: US Internal Revenue Service (IRS). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.