Sales Tax Calculator
Add sales tax to a pre-tax price, or find the tax already included in a receipt total. Enter the applicable rate yourself. This calculator does not claim to know local rates, exemptions or the taxability of an item.
Your result
How the calculation works
Add tax: tax = pre-tax price × rate; total = price + tax. Reverse tax: pre-tax price = inclusive total / (1 + rate); tax = inclusive total − pre-tax price. Monetary results reconcile after rounding to the selected currency’s minor unit.
Worked example
At 8.25%, a $100 pre-tax price has $8.25 tax and a $108.25 total. Reverse a $108.25 total at the same rate to recover $100 before tax and $8.25 tax.
Assumptions and limitations
One user-entered ad valorem rate applies to the entire amount. USD/CAD/GBP/AUD/EUR/NZD/INR round to two decimals and JPY to whole units. Inclusive totals are preserved: reverse calculation rounds the base, then uses the remainder for tax. No location, exchange-rate or exemption database is loaded.
Confirm the legally applicable rate and taxable base from the relevant tax authority. Receipt line-level rounding can differ from tax applied to a combined total. Currency changes presentation only. This is a calculation rather than tax advice or a compliance determination.
Method reviewed 2026-10-08. Calculation standards · Report an issue