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Sales Tax / VAT / GST Calculator

Add or extract sales tax, VAT or GST from any amount at a chosen rate.

Runs in your browser — files never leave your device

Net
$100
Sales tax
$7
Gross
$107

How it works

The calculator works in two directions. In the default mode it adds tax to a pre-tax amount, the way a US register does. With the inclusive box ticked it extracts tax that is already inside a total, which is how you analyze a receipt or a VAT-inclusive price. Because sales tax, VAT and GST are all a single percentage applied to a price, the same math serves all three — only the rate and the name change.

The exact formulas used:

  • Adding: tax = net × rate ÷ 100, and gross = net + tax
  • Extracting: net = gross ÷ (1 + rate ÷ 100), and tax = gross − net

A worked example at the defaults: $100 at 7% adds $7 of tax for a gross of $107. Run it backward and a $107 tax-inclusive total at 7% returns the same split: $100 net and $7 tax. The common mistake is multiplying the gross by the rate — 7% of $107 is $7.49, not the true $7 — because the tax was charged on the net price, so extraction requires division, not multiplication.

Which rate to enter depends on where you are. US rates combine a state rate with city and county add-ons, so they vary block by block from 0% to over 10% (as of 2025) — copy the combined rate from a receipt. VAT and GST countries set national rates and quote prices tax-inclusive, so use the extract mode there; the country pages below preload each country’s typical rate and label.

Country versions: United States (Sales Tax), United Kingdom (VAT), Canada (GST/HST), Australia (GST).

Estimates only — tax rates change and some goods are exempt or taxed at reduced rates, so confirm the rate that applies to your purchase.

Frequently asked questions

Can it extract tax from a tax-inclusive total?
Yes — tick the inclusive option and the tool divides by (1 + rate) instead of multiplying. A $107 total at 7% splits into a $100 net price and $7 of tax. This is the right way to back tax out of a receipt, an invoice or any price quoted with tax included.
Why can’t I just multiply the total by the rate to get the tax?
Because the tax was charged on the net price, not on the total. Multiplying the $107 total by 7% gives $7.49, overstating the true $7 of tax. Dividing the total by 1.07 recovers the original $100 base, and the tax is whatever is left over.
What rate should I enter in the US?
Use your combined state plus local rate, since cities and counties add their own percentages on top of the state rate. Five states — Alaska, Delaware, Montana, New Hampshire and Oregon — charge no statewide sales tax (as of 2025), though some Alaska localities levy their own. Your last receipt or your state revenue department’s website will show the exact combined rate for your location.
What is the difference between sales tax, VAT and GST?
For a shopper the arithmetic is identical — a single percentage on the price — which is why one calculator handles all three. The practical difference is display convention: US shelf prices exclude sales tax, while VAT and GST countries must show tax-inclusive prices. So in the UK, Australia or India you will usually want the extract mode to see the tax inside a price.
How does the calculator round?
Net, tax and gross are each rounded to 2 decimal places (cents). For example, extracting 7% from $19.99 gives a net of $18.68 and tax of $1.31, which add back to $19.99 exactly. Real receipts that round line by line can differ from a single-total calculation by a cent.
What do the country versions preload?
Each variant page starts with that country’s typical rate and tax name — 20% VAT for the UK, 5% GST for Canada, 10% GST for Australia and a 7% placeholder for the US (as of 2025) — while this page defaults to 7%. The rate box stays fully editable, so adjust it for HST provinces, reduced VAT bands or your local combined rate.
Is my data uploaded?
No — the calculation runs in your browser and nothing you type leaves your device.

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