The kilogram, as of 2019, is defined by the International Bureau of Weights and Measures from the fixed numerical value of the Planck constant (h).

The word gramme was adopted by the French National Convention in its 1795 decree revising the metric system as replacing the gravet (introduced in 1793 simultaneously with a base measure called grave, of which gravet was a subdivision).

This word—ultimately from Greek γράμμα (grámma), "letter"—had adopted a specialised meaning in Late Antiquity of "one twenty-fourth part of an ounce" (two oboli),[8] corresponding to about 1.14 modern grams.

This use of the term is found in the carmen de ponderibus et mensuris ("poem about weights and measures") composed around 400 AD.

The gram is the most widely used unit of measurement for non-liquid ingredients in cooking and grocery shopping worldwide.