Sales Tax Calculator

Two directions, one rate

Retail arithmetic splits into exactly two jobs: putting tax on top of a pre-tax price, and pulling it back out of a tax-inclusive one. This page runs both. Add mode multiplies the price by (1 + rate ÷ 100); extract mode divides by the same factor. The outputs mirror a receipt — the total, the pre-tax price and the tax itself — so the panel is as useful for a market stall writing prices as for a customer checking the tax inside a total at a restaurant in a rate they do not know by heart.

The rate you enter is the whole truth: sales tax is cumulative across state, county and city, and the tool does not try to know where you are. "8.25%" is a choice, not an assumption — enter the combined rate from your authority, and everything else follows.

A worked example, step by step

Problem: a gadget costs 100 pre-tax and the combined rate near you is 8.25%. Then, the reverse: a colleague paid 214.20 at a counter in a 5% zone; what was the pre-tax price?

1. Add mode: 100 × 1.0825 = 108.25. The tax is 8.25, exactly the sticker promise.
2. Extract mode: 214.20 ÷ 1.05 = 204.00. The tax is 214.20 − 204.00 = 10.20.
3. Sense-check the extract: 204 × 1.05 = 214.20 ✓, so the counter's zone does apply 5%.
4. Note the asymmetry: 214.20 minus 5% would be 203.49, one-euro off — dividing by 1.05 is the correct move, always.
5. Round only at the end: 300 at the same 8.25% is 324.75 in one multiplication, not 324.75 built from per-item roundings.

The fourth step is the one that saves arguments: subtracting the rate from a gross number is the most common tax error in receipts, and it always lands lower than the real pre-tax price because the tax base is the smaller, cleaner amount.

One price under six combined rates

For a 300 item, the same pre-tax figure under different levels of combined tax:

The 8.875% row is worth a second look: rate 8.875 on 300 is 26.625 — exactly on the half-cent boundary — which money display rounds to 26.63, and the total follows at 326.63. Rounding is a presentation rule, not a maths rule; keep the full precision through the computation and round once at display.

Extract mode for receipts and refunds

Extract answers the questions receipts do not: "of this gross, how much is tax?" — for a 214.20 sale at 5%: 204.00 pre-tax, 10.20 tax. It also covers refunds in the other direction: a gross refund of 214.20 returns the customer 204.00 in product value and 10.20 in tax, and a business filing filing uses exactly those two numbers. The same tool covers invoices where prices were agreed tax-inclusive — a quote "214.20 including 5%" splits perfectly into 204.00 plus 10.20, which is what the books actually need.

Mistakes that quietly shrink the pre-tax price

• Subtracting the rate from the gross. 214.20 with 5% "taken off" becomes 203.49, not the true 204.00.
• Using only the state rate. Local add-ons matter; combined is what multiplies.
• Rounding per item before totalling. Rounding only once at the end matches how the tax authority does it.
• Applying the tool to a rate above 100%. The rate field permits large values, but real combined rates are never that odd; a 100 entry usually means a paste error.
• Confusing sales tax with VAT. VAT applies at each stage and is reclaimed; sales tax applies at the final sale — different mechanics, different bookkeeping.

Keep exploring

• VAT Calculator — the same two moves for VAT-inclusive invoices at European rates.
• Tip Calculator — a social-percentage add-on that behaves like a flat rate on the pre-tax base.
• Markup Calculator — pricing your own goods: cost, markup, then tax last.
• Guide: VAT and Sales Tax Explained.