The main difference between Acre and Hectare is that the Acre is a unit of area and Hectare is a metric unit of area.
The acre is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet), which is exactly equal to 10 square chains, 1⁄640 of a square mile, or 43,560 square feet, and approximately 4,047 m2, or about 40% of a hectare.
The acre is a statute measure in the United States and was formerly one in the United Kingdom and almost all countries of the former British Empire, although informal use continues.
The international symbol of the acre is ac. In the United States both the international acre and the US survey acre are in use, but they differ by only two parts per million: see below. The most common use of the acre is to measure tracts of land. The acre, based upon the International yard and pound agreement of 1959, is defined as exactly 4,046.8564224 square metres.
Traditionally, in the Middle Ages, an acre was defined as the area of land that could be ploughed in one day by a yoke of oxen.
The hectare (; SI symbol: ha) is an SI accepted metric system unit of area equal to a square with 100 metre sides, or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about 0.405 hectare and one hectare contains about 2.47 acres.
In 1795, when the metric system was introduced, the “are” was defined as 100 square metres and the hectare (“hecto-” + “are”) was thus 100 “ares” or 1⁄100 km2. When the metric system was further rationalised in 1960, resulting in the International System of Units (SI), the are was not included as a recognised unit. The hectare, however, remains as a non-SI unit accepted for use with the SI units, mentioned in Section 4.1 of the SI Brochure as a unit whose use is “expected to continue indefinitely”.The name was coined in French, from the Latin ārea.
An English unit of land area (symbol: a. or ac.) originally denoting a day’s plowing for a yoke of oxen, now standardized as 4,840 square yards or 4,046.86 square meters.
Any of various similar units of area in other systems.
A wide expanse.
“I like my new house – there’s acres of space!”
A large quantity.
The length, English units of length equal to the statute dimensions of the acre: 22 yds (≈20 m) by 220 yds (≈200 m).
A duel fought between individual Scots and Englishmen in the borderlands.
A unit of surface area (symbol ha) equal to 100 ares (that is, 10,000 square metres, one hundredth of a square kilometre, or approximately 2.5 acres), used for measuring the areas of geographical features such as land and bodies of water.