hecto-

[French, alteration of Greek hekaton, hundred.]

[Etymology: Gk: ‘hundred’] Symbol h- since 1960, but H- prior to 1960. (Metric) The 100 multiplier, e.g. 1 hectogram = 1 hg = 100 g. Contractable to hect- before a vowel, e.g. hectare = 1 ha = 100 a.

Though used extensively in Europe, the hectometre, hectogram, and hectolitre are little recognized, so undesirable elsewhere. However, the hectare has become the effective base unit for land area in many jurisdictions while the hectopascal is common on meteorological maps. The long-established practice of expressing atmospheric pressure using the millibar, which is identical with hectopascal, has prompted the standard use of hPa as the SI unit.

The hectometre is not legal in the UK for trade.The UK Weights and Measures Act 1985 explicitly excluded from use for trade the bushell, cental, chain, drachm, dram, fluid drachm, furlong, grain, hundredweight, ounce apoth., peck, pennyweight, quarter, quintal, rood, scruple, stone, ton, the square mile, cubic inch, cubic foot, cubic yard, and the term ‘metric ton’. However, the legal status of the bushell, fluid drachm, and peck had been repealed, along with all apothecaries' units and troy units other than ounce, by Order in 1970. Besides the remaining BI units and the simple SI units, the Act included the kilometre, decimetre, centimetre and millimetre, the square metre, square decimetre, square centimetre and square millimetre, the hectare and decare along with the are, the cubic metre, cubic decimetre and cubic centimetre, the hectolitre decilitre, centilitre and millilitre, the tonne (or ‘metric tonne’), kilogram, hectogram, milligram and carat (metric). All had been included in the similar Act of 1963, but with some variation of name: -gram was -gramme, decare was dekare, the tonne appeared only as metric ton.

One hundred (10²): hectogram.