Sometimes the only number you have is the final total, and you need the price before tax — for an expense report, a refund, or simply to check a receipt.
This version is set to tax-inclusive mode, so the amount you enter is treated as the total the customer paid. Press Compute and you get the pre-tax amount, the tax that was hidden inside it, and the total you started with.
The arithmetic behind it: pre-tax amount = total ÷ (1 + rate ÷ 100). At 6%, $106 ÷ 1.06 = $100, so the tax inside that total was $6.
For informational purposes only — not financial advice.
How to use
- Enter the price or the tax-inclusive total.
- Enter the sales tax rate you are charged — 6% is a common state base.
- Choose whether your amount is pre-tax or already includes tax.
- Press Compute to see the pre-tax amount, the tax and the total.
- For an exact receipt figure, use your combined local rate with its decimals.
Frequently asked questions
How do I remove sales tax from a total?
Divide the total by 1 plus the rate expressed as a decimal. At 6%, divide by 1.06. A $106 total becomes $100 pre-tax with $6 of tax, which is exactly what this calculator returns.
Why can't I just subtract the rate from the total?
Because the rate was applied to the smaller pre-tax amount, not to the total. Subtracting 6% of $106 would give $99.64, but the correct pre-tax amount is $100 — the two differ by the tax that was levied on the tax.
How do I find the tax rate if I only know the total and the pre-tax price?
Subtract the pre-tax price from the total to get the tax, divide that tax by the pre-tax price, then multiply by 100. A $6 tax on a $100 sale is 6 ÷ 100 × 100 = 6%.
Does this work for any tax rate?
Yes — any rate, including combined city and county rates with decimals. Enter the rate you were actually charged, such as 8.875%, and the reverse calculation stays accurate.
Where is a reverse tax calculation useful?
Expense reports, bookkeeping, refunds, checking a receipt, and pricing decisions where you know what the customer must pay and need to know what you keep before tax.