20 May is observed as a World Metrology Day every year. Many nations on this day, internationally collaborate to create awareness about metrology and its advancement in the respective field.

The theme for 2021 is Measurement for Health. This theme was chosen to create awareness of the important role measurement plays in health, and thus in the wellbeing of every one of us.


The Day is an annual celebration of the signature of the Metre Convention on 20 May 1875 in Paris by representatives of 17 nations. The World Metrology Day project is realized jointly by the International Organization of Legal Metrology and Bureau International des Poids et Mesures.

20 May World Metrology Day