Acre
Area
That is
4,047 m²
1 acre (statute acre)
The other way round: 1 ha is 2.4711 acres.
- Period: c. 1300 to today
- Region: England, later the UK
- Goods: farmland
Values
| Value | That is | Period | Used for |
|---|---|---|---|
| statute acre | 4,047 m² | c. 1300 to today | farmland · England, later the UK |
| Irish (plantation) acre | 6,555 m² | 16th century to the 19th | land · Ireland |
| Cheshire acre | 8,562 m² | to the 19th century | land · Cheshire and parts of Lancashire and Staffordshire |
| Scots acreSources give 5080 m² and 5142.5 m², a difference of 1.2%, because the length of the Scots fall is disputed. | 5,080–5,143 m² | to 1685, in use into the 19th century | Scotland |
What the unit was used for
The acre is a strip rather than a square: one chain wide and one furlong long, the shape a team pulling a plough actually left behind in an open field.
Most of the 1305 Statute for the Measuring of Land is a list of paired lengths and breadths that multiply to 160 square perches, running from 10 rods by 16 down to 80 by 2.
It survived every reform because land changed hands by it, and it is still used in UK land registration today.
The statute acre rests on the perch of 16½ feet, which is why the number 4840 square yards looks so arbitrary.
It also varied by nation: the Irish plantation acre is 1.62 statute acres, the Cheshire acre 2.12 and the Scots acre roughly 1.26.
In the system
1 acre = 4 roods = 160 square perches = 10 square chains, and it is one chain by one furlong
A story you will often hear
An acre is often said to be the area a team of oxen could plough in a day.
What the evidence shows: Andrew Jones’s study of English manorial records finds six different perches on the Bishop of Ely’s manors alone in 1251, and perches from 15 to 25½ feet elsewhere. He separates the standard 4 by 40 acre from local acres measured on quite another basis, records custumals in which ploughmen ploughed a larger acre on their own land than on the lord’s, and concludes that the origin of the 16½-foot perch will probably never be established.