World Metrology Day is an annual celebration of the signature of the Metre Convention on 20 May 1875 by representatives of seventeen nations. The Convention set the framework for global collaboration in the science of measurement and in its industrial, commercial, and societal applications. The original aim of the Metre Convention – the worldwide uniformity of measurement – remains as important today as it was in 1875.
The theme for World Metrology Day 2025 is Measurements for all times, for all people.
This year, National Metrology Institutes (NMIs) around the world will celebrate the 150th anniversary of the signing of the Metre Convention – a milestone that underscores a century and a half of international collaboration in measurement science.
