The workings, in plain sight
Sources & calculation method
The VAT uses published Irish rate presets and straightforward arithmetic. The source checks below were completed on 19 October 2026.
Official sources
- Revenue: current VAT rates — rate percentages and the separate farmers’ compensation percentage.
- Revenue: VAT rates database — look up the treatment of specific goods and services.
- Revenue: second reduced rate — qualifying supplies and effective dates.
- Revenue: zero rate — qualifying zero-rated supplies.
How the calculator works
For adding VAT: VAT = net × rate ÷ 100; gross = net + VAT. For removing VAT: net = gross ÷ (1 + rate ÷ 100); VAT = gross − net.
Our rounding convention
We use integer cents and round to the nearest cent, half up. When adding, VAT is rounded first; when removing, net is rounded first. The other figure is derived so net + VAT = gross. This is the calculator’s stated convention, not a claim that every invoice must use the same rounding method. Reversing a rounded amount can differ from the original by a cent.
What the result means
The result is a single calculation at your selected rate. It is not an invoice, a VAT return, a determination of the applicable rate or advice about VAT registration, exemption or reverse-charge accounting. We do not automatically choose a rate for your business.
Privacy and sharing
Your calculation runs locally. WhatsApp sharing and copy links contain the figures you choose to share. Read the privacy information.