Sales Tax Calculator

Calculate sales tax two ways: add tax to a known pre-tax price, or work backward from a tax-inclusive total to find the original price and tax amount.

How It Works

The calculation, explained

Add mode: total = amount × (1 + rate). Extract mode: pre-tax price = amount ÷ (1 + rate), with the tax amount as the difference. See our Sales Tax on Invoices guide for how to find the correct rate for your state.

Worked Examples

Sales tax calculation examples

ScenarioCalculationResult
Add 8.25% tax to $240$240 × 1.0825Total $259.80 (tax $19.80)
Price includes 7% tax: $107$107 ÷ 1.07Pre-tax $100.00 (tax $7.00)
Add 6% tax to $1,499.99$1,499.99 × 0.06Tax $90.00, total $1,589.99
Combined rate: 4% state + 2.5% local on $80$80 × 6.5%Tax $5.20, total $85.20

A common mistake when backing tax out of a tax-inclusive price is to subtract the percentage directly ($107 − 7% = $99.51). That’s wrong — always divide by (1 + rate).

US Sales Tax

How US sales tax rates work

  • Combined rates: the rate you charge is usually the state rate plus county, city and special-district rates. Combined rates in some places exceed 9%.
  • No statewide sales tax: Alaska, Delaware, Montana, New Hampshire and Oregon have no statewide sales tax (Alaska allows local sales taxes).
  • Origin vs destination: most states use the buyer’s location (destination-based) to determine the rate; a few use the seller’s location for in-state sales.
  • Nexus: since the 2018 Wayfair decision, remote sellers may have to collect tax in states where they exceed economic thresholds — often $100,000 in sales — even without a physical presence.
  • Taxable items vary: groceries, clothing, digital products and services are taxed differently from state to state.

Our guide Sales Tax on Invoices: A US Guide explains how to show tax correctly on your invoices.

VAT & GST

Using the calculator for VAT and GST

The same maths works for value-added tax and goods-and-services tax. Enter the standard rate for your country — for example 20% VAT in the UK, 19% in Germany, 10% GST in Australia, 5% GST in Canada (plus provincial tax in some provinces), or the GST slab that applies in India. Use “add tax” for net prices and “extract” for VAT-inclusive prices.

FAQs

Common questions

Does this account for different tax rates by state or country?

No — enter the specific rate that applies to your transaction; rates vary widely by jurisdiction and even by product category.

What’s the difference between the two modes?

Add mode is for pricing you set before tax; extract mode is for figuring out the tax embedded in a price that’s already tax-inclusive.

How do I calculate sales tax?

Multiply the pre-tax price by the tax rate as a decimal. For 8% tax on $50: $50 × 0.08 = $4 tax, for a total of $54.

How do I remove tax from a total?

Divide the tax-inclusive total by (1 + tax rate). For $108 including 8% tax: $108 ÷ 1.08 = $100 before tax; the tax is $8.

Should sales tax be shown separately on an invoice?

Yes. Show the taxable subtotal, the rate and the tax amount separately — it’s clearer for the customer and often required by tax rules.

General information only. This page explains common practice and is not legal, tax, accounting or financial advice. Rules differ by country, state and industry and change over time — check the requirements that apply to you, or ask a qualified professional, before relying on it. Templates and calculators are provided as-is; you are responsible for the documents you create. Read our full disclaimer.
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