Calculators
Reverse sales tax calculator
From the amount you paid back to the price on the tag, and the tax hidden in between.
Checked by Radif Partners · Editorial policy · How we calculate
To take sales tax out of a total, divide the total by one plus the combined rate: a $54.13 receipt in Texas, where the state rate is 6.25%, with a 2% local rate, was $50.00 before tax and included $4.13 of tax. That shortcut only works when the whole purchase was taxed at one rate. If the receipt mixed exempt groceries and taxable goods, or if a clothing threshold applied, dividing by the full rate gives the wrong answer. This calculator solves the forward rule of the state you pick instead: choose the state, type the local rate and the category, and it finds the pre-tax price that the register would have turned into your total. Expense reports, VAT-style bookkeeping for a small business, and checking whether a seller charged the right tax are the usual reasons to run it.
Price before tax
$50.95
Sales tax $3.18 · 6.241% of the price
| Price before tax | $50.95 |
| State tax · 6.25% | $3.18 |
| Local tax · 0% | $0.00 |
| Total | $54.13 |
Rule applied: general state rate. Exact local rate for an address: Texas rate lookup. How this is calculated.
The formula, and when it breaks
Price before tax = total ÷ (1 + rate). With a combined rate of 8.25%, a $108.25 total gives $100.00; the tax is the difference. Subtracting 8.25% of the total instead, a common shortcut, removes too much, because the tax was calculated on the smaller pre-tax price, not on the total.
The formula breaks in three situations. First, when part of the receipt was exempt, such as groceries in a state that exempts them: only the taxable lines carry tax, so the rate applies to a smaller base. Second, with a per-item clothing threshold: in Massachusetts only the part of an item's price above the threshold is taxed, so a $212.50 total for one jacket means a price of $210.29, not the result of dividing by 6.25%. Third, when the seller rounded per line rather than on the total, which can leave a one-cent gap. The calculator above handles the first two through the category menu; for a mixed receipt, run it once per category.
Finding the right combined rate
The state part is filled in for you. The local part depends on where the sale took place, or the delivery address for shipped goods, and the state's address lookup gives it exactly. If the receipt prints the rate, use that: it is what the register applied. If it prints only the tax amount, you can work back to the rate by dividing the tax by the pre-tax subtotal.
Checking a seller's tax
Run the forward calculator with the price on the tag, then compare the tax with the receipt. A difference of a cent is rounding; a larger gap usually means the wrong local rate, an exemption the seller missed or applied by mistake, or a shipping charge taxed in a state that exempts it (or the reverse). The sales tax calculator does the forward direction, and each state page lists its exemptions.