The EU uses the International System of Units (SI), the modern metric system. This page explains the EU rules on units of measurement and links to the main legislation and background documents.
EU legislation
Rules on units of measurement in the EU are set out in Directive 80/181/EEC, as last amended by Commission Directive (EU) 2019/1258.
A summary of the legislation is available in all official EU languages.
Review and updates
2020 – Preparatory study on market conditions and implementation of Directive 80/181/EEC
2019 – Commission Directive (EU) 2019/1258 adapted the definitions of the SI base units to technical progress
2009 – Directive 2009/3/EC updated Directive 80/181/EEC
For the 2009 update, the Commission published the following documents in 2006-07
- Legislative proposal – COM(2007) 510
- Impact assessment – SEC(2007) 1136
- Impact assessment summary – SEC(2007) 1137
- Report on the public consultation
- Commission staff working document
