SALES TAX CALCULATOR
$100.00 × 8.875% = $8.88 tax. Gross $108.88. Two-decimal rounding. Enter your local tax rate. Rates vary by state, city, and product type. This calculator does not look up rates by location.
Updated May 2026 · Built by Lukáš, an architect in Prague.
Formula, assumptions, rounding & limitations
Formula
- Add tax:
gross = net × (1 + rate ÷ 100) - Remove tax:
net = gross ÷ (1 + rate ÷ 100) tax amount = gross − net
Assumptions
- The rate you enter is the combined rate (state + county + city + any special district), expressed as a percentage.
- The same rate applies to the entire price — no per-line mix.
- Both decimal comma (8,875) and decimal point (8.875) are accepted.
Rounding
- Net, gross, and tax amounts are rounded to 2 decimal places for display.
- Receipts may differ by a cent or two because stores round each line item before summing.
Limitations
- This calculator does not look up rates by location. Look up your local rate before relying on the result.
- Category-specific rates (food, clothing, prescriptions in some US states; reduced VAT bands in the EU) are not modelled.
- Sales-tax holidays and exemptions are not detected.
How do I add sales tax to a price?
Multiply the price by 1 plus the tax rate as a decimal: final price = price × (1 + rate ÷ 100). For $100 at 8% tax, $100 × 1.08 = $108. Set the calculator to “Add tax” mode (the default) and enter your local rate. To go the other way — find the pre-tax price from a tax-included total — switch to “Remove tax” mode.
What’s the sales tax rate in my state?
This calculator does not look up rates by location — you enter the rate yourself. Combined state + local rates in the US range from 0% (NH, OR, MT, AK, DE) to roughly 9.55% (TN). City and county add-ons vary; the receipt or your state’s tax site has the exact number.
Why do I get a slightly different number than the receipt?
Most often it’s rounding. Stores round each line item, so the receipt total can differ by a cent or two from a calculation done on the subtotal. Some jurisdictions also tax certain categories (food, clothing) at different rates than general goods.
How do I remove tax from a total that includes it?
Switch the calculator to “Remove tax” mode. If you paid $108 at an 8% rate, the original was $108 ÷ 1.08 = $100, and the tax was $8.
Is sales tax the same as VAT?
Mathematically yes — both are a percentage added to a price. The legal and accounting differences (who collects, who can reclaim, when it’s due) are different, but for figuring out a final price the formula is identical.