3 VAT Calculators, Compared Honestly

An invoice says £480 and you need to know how much of that is VAT. Dividing by 1.2 gives the net; subtracting 20% does not, and the two answers differ by enough to matter on a tax return.

That asymmetry catches people constantly. Adding VAT multiplies by 1.2; removing it divides by 1.2. Taking 20% off a gross figure understates the net every time, and at 20% the error is about 4% of the total. A calculator prevents that specific mistake, which is most of the reason to use one.

How to judge a VAT calculator

Does it do reverse VAT properly? Extracting VAT from a gross amount is the calculation people get wrong, and it should be an explicit mode rather than something you improvise.

Can you set any rate? 20% and 5% cover the UK. Anything international needs an arbitrary percentage — VAT rates across the EU alone run from single digits to 27%.

Does it show all three figures? Net, VAT and gross together, so you can check the result against the invoice rather than reverse-engineering one number.

What is it actually selling? Most free VAT calculators are lead generation for accounting software. That does not make them wrong, but it explains the sign-up prompts.

The comparison

Facts checked August 2026; rates and tools change. Table covers only the 3 alternatives — our tool gets its own section below.

HeLovesMath VAT Calculator

The broadest of the three. It carries rates for more than 30 countries across the UK, EU, Middle East, Asia-Pacific and the Americas, and offers add, remove and reverse VAT as three explicit modes via a toggle — which removes the ambiguity about which direction you are calculating in, the exact place people go wrong.

Free with no registration. One note: the page describes itself as being for educational use, which is a sensible disclaimer rather than a functional limit, but it means you should still check the rate against an official source before it lands on an invoice.

Enerpize VAT Calculator

The most instructive. Alongside adding VAT to a net price and removing it from a gross one, it shows the formulas it is using — Net × (1 + VAT Rate) = Gross and Gross ÷ (1 + VAT Rate) = Net — which is worth more than the answer, because seeing the division makes the “don’t subtract 20%” point obvious.

It comes pre-set to the UK’s 20% and the rate is adjustable for other countries. The calculator needs no account, and the page promotes Enerpize’s accounting product, which is the business model rather than a catch.

FreeAgent VAT Calculator

The simplest, from an established UK accounting software company. Enter an amount, choose add or remove, pick standard 20% or reduced 5%, and read the VAT and the final price. No account, free, four inputs.

The limitation is right there in the design: those two rates only. For UK work at standard or reduced rates it is quick and unambiguous; for the zero rate, an EU rate, or anything else, it cannot help you. Like Enerpize, it exists partly to introduce you to the accounting platform behind it.

VAT Calculator

Ours adds VAT to a net figure or works backwards to strip it out of a gross one, at any rate you enter, showing net, VAT and gross together — and it runs entirely in your browser with no account and no upsell attached.

What it does not do: carry a built-in table of country rates, so you supply the percentage yourself. That is a real trade-off — HeLovesMath’s 30+ preset rates save a lookup — but it also means no chance of applying a rate that changed since the tool was last updated. For the authoritative figures, the European Commission’s VAT pages are the source for EU rates, and your own tax authority for everywhere else.

Which one to pick

• Working across several countries — HeLovesMath’s preset rates.
• Explaining the calculation to someone — Enerpize, for the formulas.
• UK standard or reduced rate, quickly — FreeAgent.
• An unusual rate, with all three figures shown — the tool below.

How to do it with VAT Calculator

1. Open the VAT Calculator and enter the amount.
2. Say whether that amount is net or gross — this is the decision, not the rate.
3. Enter the rate that applies to the transaction, not the country’s headline rate.
4. Read net, VAT and gross together and check the gross against your invoice.

The walkthrough is in how to add or remove VAT from a price. Other finance tools are in the tools directory.

You might also need

For US-style sales tax, which works differently from VAT, the Sales Tax Calculator is the right tool.

If the figure is going onto a document, the Invoice PDF Generator handles the paperwork around it.

Frequently asked questions

Is there a free VAT calculator that doesn’t need an account?

All four here are free with no account. The difference is what surrounds them — two are attached to accounting software — and whether you can set an arbitrary rate.

How do I remove VAT from a gross price?

Divide by 1 plus the rate. At 20%, divide by 1.2; the VAT is the difference. Subtracting 20% from the gross gives the wrong answer, and it is wrong in the direction that understates your net figure.

Which VAT rate applies to my sale?

That depends on what you are selling and where the customer is, not just on the country you are in — reduced and zero rates cover specific goods and services, and cross-border rules add more. A calculator applies the rate you give it; deciding the rate is a question for your tax authority or accountant.

Final thought

Decide whether your number is net or gross before you touch a calculator. Every VAT mistake worth catching comes from that one question being answered wrong, and no tool can tell which you meant.

Try the free VAT Calculator