VAT Calculator
Add VAT to a net amount or take it out of a gross amount, at the rate you enter, and see the net, VAT and gross side by side.
Your numbers
The values filled in are an example. The 20% rate isn't any particular country's rate.
The price or invoice total before VAT is added.
The rate that applies to this sale. Check the rate with the tax authority where you work.
VAT
$20.00
Gross (including VAT)
$120.00
Breakdown
- Net (entered)
- $100.00
- VAT at 20% (net × rate)
- $20.00
- Gross (net + VAT)
- $120.00
The VAT is rounded to the cent, half a cent or more up, and the other amount is worked out from it, so net + VAT always equals gross.
How VAT Is Added and Removed
Formulas the calculator uses
- Add VAT to a net amount: VAT = net × rate ÷ 100, and gross = net + VAT.
- Remove VAT from a gross amount: VAT = gross × rate ÷ (100 + rate), and net = gross − VAT. This is the same as net = gross ÷ (1 + rate as a decimal).
Worked examples
These use a 20% rate as a sample input. It isn't any particular country's rate.
- Add VAT: $100.00 net × 20% = $20.00 VAT, so the gross is $120.00.
- Remove VAT: $100.00 gross × 20 ÷ 120 = $16.666…, which rounds to $16.67 VAT, so the net is $100.00 − $16.67 = $83.33. Check: 20% of $83.33 is $16.67.
- A common mistake: taking 20% off the gross gives $80.00, which is too low, because the VAT is 20% of the net, not of the gross.
Rounding
The calculator rounds the VAT to the cent and works out the other amount from it, so net + VAT always equals gross. A fraction of a cent rounds the way OpenStax's Contemporary Mathematics, section 6.2 describes for sales tax: “round up for half a penny or more, but round down for less than half a penny.” For example, 5% of $10.10 is $0.505, which rounds to $0.51. Tax authorities can set their own rounding rules for invoices, so check the rules where you work.
Source opened and quoted on October 29, 2026.
Rates and inputs
The calculator doesn't include any country's VAT rates: the rate is always the one you enter. Rates depend on the country and on what you sell, so check the rate with the tax authority where you work. The amount can be $0 to $1,000,000,000,000, entered to the cent, and the rate 0% to 100%. Negative numbers and values outside these limits show a message.
Related tools: the sales tax calculator and the invoice total calculator. More background: what is a VAT invoice.
Frequently Asked Questions
Put the Right Tax on Your Invoices
Save your tax rates and settings in Billed once, and it works out the tax for you whenever you create an invoice or estimate.
No credit card required.