Area size with 10,000 m² (corresponds approximately to a football field 120 x 80 m); one square kilometre is 100 hectares. The word hectare is composed of the Greek hekt(o) for "hundred" and ar and means 100 ares. Hectare is common in European viticulture for the indication of vineyard areas. The maximum yield of wine, defined differently per region, area or appellation according to the wine laws of each country, is expressed in hectolitres (100 litres) of grape must or kilograms of grapes per hectare (yield per hectare). The acre common in England and the USA corresponds to 0.405 hectares (just under 2.5 acres/ha). One hectare consists of four acres (old area measure). See also the World Ranking List of Grape Varieties by area under Grape Variety, as well as other common units of measurement under Area Measurements and Hollow Measurements.