VAT / sales tax calculator
Add tax to a net price or strip it from a gross price — enter either amount and the other updates instantly.
Enter a net price (ex-tax) or a gross price (inc-tax) and a tax rate. Both price fields update each other — change either one to recalculate. Quick presets cover the most common VAT and GST rates.
VAT and sales tax calculator inputs and results
Your numbers
The price before tax is added. Change this to calculate gross.
The price the customer pays. Change this to strip out the tax.
Enter any rate, or use a preset below.
UK 20% · EU 19–25% · AU/NZ 10–15% · US varies
Result
Tax amount
$20.00
20% of $100.00 net
Price breakdown
How this calculator works
Adding tax: gross = net × (1 + rate). At 20%, a $100 net price becomes $120 gross — the tax is exactly 20% of the net. Removing tax: net = gross ÷ (1 + rate). At 20%, a $120 gross price becomes $100 net — which is gross ÷ 1.20, not gross × 0.80. These two operations are inverses of each other, so entering the same value in either field always produces the same tax amount.
The tax as a share of gross is always less than the stated rate. At 20% VAT, the tax is 16.67% of the gross price (20 ÷ 120), not 20%. This is why subtracting the rate percentage directly from a gross price gives the wrong answer — and why the correct reverse calculation divides rather than subtracts.
About this tool
This tool adds tax to a net price or removes it from a gross price, with both fields updating each other in real time. Inputs: net price (excluding tax), gross price (including tax) — enter either and the other is calculated — and a tax rate percentage. Common rate presets are provided for UK VAT, EU VAT, Australian GST, and US sales tax ranges. Output: the tax amount, net price, and gross price at the entered rate.
Frequently asked questions
What's the difference between VAT and sales tax?
Both are consumption taxes collected on the sale of goods and services, but they work differently. VAT (value-added tax) is collected at every stage of the supply chain — each business charges VAT on its sales and reclaims the VAT it paid on its purchases, remitting only the difference to the government. Sales tax, as used in most US states, is collected only at the final sale to the end consumer and is not reclaimed at earlier stages. For calculating the tax on a single transaction, the arithmetic is identical — the rate is applied to the pre-tax price.
How do I remove tax from a gross price?
Enter the gross (tax-inclusive) price in the gross field and leave the net field blank — the calculator works it out. The formula is net = gross ÷ (1 + rate). For a 20% VAT rate, that's gross ÷ 1.20. A common mistake is subtracting 20% of the gross price directly, which gives the wrong answer because 20% VAT on the net is not the same as 20% of the gross — it's approximately 16.67% of the gross.
Why can't I just subtract the tax rate percentage from the gross price?
Because the tax rate is applied to the net price, not the gross. If net is $100 and VAT is 20%, the gross is $120. The $20 tax is 20% of the $100 net, but only 16.67% of the $120 gross. Subtracting 20% from $120 gives $96, not $100 — an error of $4 per transaction. The correct reverse calculation divides by (1 + rate), not subtracts the rate percentage.
What rate should I use?
UK standard VAT is 20% (reduced rate 5%). Most EU countries apply 19–25% on standard goods. Australian GST is 10%. New Zealand GST is 15%. Canadian GST is 5%, though combined HST rates in most provinces are 13–15%. US sales tax varies by state and locality, typically 0–10.25%. Use the actual rate applicable to the specific transaction — rates differ by product category in many jurisdictions.