VAT Calculator

Add or remove VAT at any rate, such as 20% or 5%: see the VAT amount and the price with and without VAT.

VAT amount

£20.00

Add VAT

Excluding VAT

£100.00

Including VAT

£120.00

Please note: This is an example calculation, not financial advice. Personal circumstances, changes in rules and rates, and additional costs are not included. If in doubt, talk to a financial adviser.

How this number is calculated

The blocks use your input. Change a value above and they update with it.

Step 1 · Rate as a factor

VAT rate (%)20 ÷ Per100 =Rate as a factor0.2

Step 2 · Amount excluding VAT

(Calculation: Add VAT) Amount£100.00 =Amount excluding VAT£100.00

Step 3 · VAT

Amount excluding VAT£100.00 × Rate as a factor0.2 =VAT£20.00

Step 4 · Including VAT

Amount excluding VAT£100.00 + VAT£20.00 =Including VAT£120.00

How the calculation works

Work out how much VAT is in a price, or what a price becomes once VAT is added. Enter any rate, so it also works for other countries and for US sales tax.

Add VAT: the VAT is the amount times the rate, and the price including VAT is the amount plus the VAT. Remove VAT: the amount excluding VAT is the amount divided by (1 + rate); the difference from the amount you entered is the VAT. All results are rounded to whole pence, half a penny upwards.

Formula

Add VAT: VAT = amount × rate ÷ 100. Remove VAT: excluding VAT = amount ÷ (1 + rate ÷ 100), VAT = excluding VAT × rate ÷ 100.

Assumptions

One VAT rate applies to the whole amount.
The rate you enter is the VAT rate that applies, such as the standard rate of 20% or the reduced rate of 5%.
Each result is rounded to whole pence, half a penny upwards.
Exemptions, the reverse charge and other special schemes are not included.

Example calculations

The button fills in the calculator above, so you can carry on from there.

Invoice, adding 20% VAT

VAT amount
£170.00

Amount £850.00 · VAT rate (%) 20 · Add VAT
Receipt, taking out 20% VAT

VAT amount
£4.00

Amount £23.99 · VAT rate (%) 20 · Remove VAT
Reduced rate of 5% VAT

VAT amount
£0.55

Amount £10.99 · VAT rate (%) 5 · Add VAT

Frequently asked questions

How do I remove VAT from a price?

Divide the price including VAT by 1 plus the rate as a decimal. With 20% VAT, divide by 1.2: a price of 120 is 100 excluding VAT, so the VAT is 20.

Why is 20% of the price including VAT not the VAT?

The rate applies to the price excluding VAT. In a price including 20% VAT, the VAT is 20/120 of the total, which is one sixth or about 16.67%.

How is VAT different from US sales tax?

VAT is charged at every step of the supply chain and is normally already included in consumer prices. US sales tax is added at the checkout and is usually not included in the price on the shelf. The rate depends on the state and often the city or county, so combine both into one rate here.

How do I add VAT to a price?

Multiply the price by the VAT rate as a decimal and add the result to the price. With 20% VAT, 100 becomes 100 + 100 × 0.2 = 120.

What is GST?

GST (goods and services tax) is the name used for VAT in countries such as Australia, New Zealand, Canada and Singapore. It is calculated the same way, so you can enter the GST rate here.

Why is my receipt a penny out?

Shops may round the VAT per item instead of over the total, which can make a difference of a penny or two. This calculator works out the VAT over the whole amount and rounds the result to the penny.

Sources and checks

Sources

VAT rates | GOV.UK (opens in a new tab)gov.uk · accessed 5 October 2026
Providing price information | Business Companion (Trading Standards) (opens in a new tab)businesscompanion.info · accessed 5 October 2026

How we check it

This calculator has 15 fixed checks: 12 calculations with a result that is fixed in advance, and 3 cases of invalid input that must be rejected. They all run automatically every time we publish; if one fails, the calculator does not go live.

See the calculations

Amount £100.00 · VAT rate (%) 20 · Add VAT → VAT amount £20.00
Amount £120.00 · VAT rate (%) 20 · Remove VAT → VAT amount £20.00
Amount £50.00 · VAT rate (%) 7.25 · Add VAT → VAT amount £3.63
Amount £10.99 · VAT rate (%) 5 · Add VAT → VAT amount £0.55
Amount £10.00 · VAT rate (%) 19 · Remove VAT → VAT amount £1.60
Amount £50.00 · VAT rate (%) 0 · Remove VAT → VAT amount £0.00
Amount £0.00 · VAT rate (%) 20 · Add VAT → VAT amount £0.00
Amount £1,000,000,000.00 · VAT rate (%) 100 · Add VAT → VAT amount £1,000,000,000.00
Amount £850.00 · VAT rate (%) 20 · Add VAT → VAT amount £170.00
Amount £23.99 · VAT rate (%) 20 · Remove VAT → VAT amount £4.00

Changes

6 October 2026: Worked examples for the UK: VAT on an invoice, VAT taken out of a receipt and the reduced rate of 5%.
6 October 2026: Separate default tax rates for the UK and the US, with a source for the average US sales tax rate.
5 October 2026: Sources added and content reviewed.
4 October 2026: First version.

Last reviewed: 6 October 2026 · How we build and check our calculators