Tax tool

Add VAT, or take it back out.

Both directions, instantly. Add tax to a net price, or reverse it out of a gross total to find the figure that actually belongs to you — with the common rates one tap away.

  • Free, no sign-up
  • Add and reverse
  • Common rates built in

VAT calculator

Free
Common rates
100.00Net — before tax
20.00Tax amount
120.00Gross — total
Runs entirely in your browser. Nothing is uploaded.

Worth knowing

The reverse calculation people get wrong.

  1. 01

    You cannot remove 20% by subtracting 20%

    This is the single most common tax error in small business bookkeeping. To strip 20% VAT out of a £120 gross figure you divide by 1.20, giving £100 net and £20 tax. Subtracting 20% of £120 gives £96 — wrong by £4, and wrong in the direction that overstates your income on every single line.

  2. 02

    Tax collected was never your money

    The tax portion of a payment is held on behalf of the tax authority until you remit it. Treating gross receipts as revenue makes a business look more profitable than it is, right up to the quarter the bill arrives. Price and forecast on net figures only.

  3. 03

    Rates are set by jurisdiction, and they move

    The presets above cover common rates, but the correct rate depends on where you are, where your customer is, and what you sold — digital goods, food and books frequently sit on reduced or zero rates. Confirm against your own tax authority before filing anything.

Questions

About this tool.

Divide the gross amount by (1 + rate ÷ 100). At 20%, divide by 1.2. The result is the net figure; the difference between the two is the tax. Switch this tool to "Remove tax" and it does exactly that.
Yes. VAT, GST and single-rate sales tax all use the same arithmetic — only the name and the rate change. Enter your rate and the maths is identical.
No. The calculation is a couple of lines of JavaScript running in your browser. Nothing is uploaded, logged or stored.
That depends on your jurisdiction and what you sold, and it is genuinely not something a calculator can decide for you. The presets are conveniences, not tax advice — check the current rate with your own tax authority or accountant.

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