) is a SI prefix
in the SI
system of units
denoting a factor of 102
Adopted in 1795, it comes from the Greek ἑκατόν hekaton, meaning hundred.
It is rarely used, except for certain specific applications:
- hectopascal, in meteorology, for atmospheric pressure, the modern equivalent of the traditional millibar.
- hectolitre, in agriculture, for liquids (notably wine and milk) and bulk commodities (e.g. grain).
- hectogram, in agronomy, for quantities of animal feed (hectogram/animal) and for measures of agricultural productivity (hectogram/hectare); also used in Italy, abbreviated as etto, for retail sale of cold cuts and meat.
- hectometre, in radio astronomy, occasionally used to indicate a radio band by wavelength