About this VAT calculator

Updated: July 2026

This site does one job: correct Irish VAT arithmetic, instantly, at the rates actually in force. The calculator adds VAT, removes VAT, totals invoice lines both ways, works backwards from a VAT amount and checks what rate a pair of figures implies. This page explains how it works underneath, because a tool asking you to trust its numbers should show its workings.

Where the rates come from

Every rate in the tool comes from Irish law as administered by the Revenue Commissioners: the Finance Acts and Revenue's published guidance and rates database. When a rate changes, as on 1 July 2026 when hospitality food and hairdressing moved to 9%, we update the tool and the affected guides together. Rates are reviewed after every October budget and at each mid-year commencement date the Finance Act sets.

How the arithmetic works

• Adding VAT multiplies the net by the rate. Removing VAT divides the gross by one plus the rate. Working back from a VAT amount divides it by the rate.
• Results display at your chosen precision, from 0 to 3 decimal places, with standard half-up rounding at the displayed precision. Two decimals, the default, matches how amounts appear on Irish invoices.
• Each result is calculated from your input directly rather than from other rounded results, which avoids the one-cent drift that chained rounding produces.

What this tool is not

It is not tax advice, and it is not affiliated with Revenue. The calculator tells you what the figures are at a given rate; whether that rate applies to your specific supply can involve judgement, and the harder cases in our guides, from the margin scheme to property, show exactly where professional advice earns its fee. For a rate question, Revenue's own rates database is the authoritative reference, and we link to it rather than compete with it.

Corrections

If you find a figure you believe is wrong, tell us through the contact page and include the calculation. Errors get fixed and noted. A calculator's only asset is being right.