Acres to Roods (ac to rood)

1 acre equals 4 roods exactly.

1 acre = 4 roods

How to convert acres to roods

To convert acres to roods, multiply the number of acres by 4. This factor is exact. To go the other way, multiply roods by 0.25.

roods = acres × 4

Example: 10 acres = 40 roods.

About these units

Acre (ac)

US & ImperialCurrent unit

43,560 square feet or exactly 4,046.8564224 m², about 40% of a hectare. Originally the area a yoke of oxen could plow in a day.

Ploughland gave the acre its name: it traces to Old Norse akr, meaning cultivated land, and is related to German Acker and Latin ager. In medieval England it was a farming measure, the land one man with a team of eight oxen could plough in a day. The traditional strip was 40 perches long and 4 perches wide, which is 660 by 66 feet, or ten square chains. The shape was never the point, and the article on the unit stresses that any area of 43,560 square feet is an acre.

An acre is 43,560 square feet, 4,840 square yards or 1/640 of a square mile, close to 0.4 hectare. For Americans, it is roughly 88 by 55 yards, about 90 percent of a football field without the end zones. The Weights and Measures Act 1878 fixed it at 4,840 square yards in Britain, where trade use ended in 1995. The 1959 international acre is exactly 4,046.8564224 m²; the US survey acre, about 4,046.872 m², differed slightly, and US survey units were retired after 2022.

1 acre = 4,046.856422 square meters (approximately).

Sources: Wikipedia: Acre; NIST Guide to the SI, Appendix B.8: conversion factors

Rood (rood)

Medieval EnglishHistorical unit (no longer in standard use)

A quarter of an acre (1,011.7 m²), 40 square rods. A medieval English land unit, the area of a furlong by a rod.

Old English rod meant a pole, and especially a cross, which is also why the word names the crucifix screens in medieval churches. As a land measure, the rood was the area of a strip one furlong long and one rod wide, which is the same as 40 square rods. That makes it a quarter of an acre, or 10,890 square feet, about 1,011.7 square meters. Its handiness for surveyors came from the simple fractions: four roods to an acre.

The medieval acre was imagined as a strip a furlong long and four rods wide, the ground a team of oxen could plough in a day, so the rood was the strip left when that width was cut into four. Records in England long gave land as acres, roods and perches, in that order. A separate and obsolete use of rood was as a length, with local values somewhere between about 16.5 and 24 feet. By the time the Oxford English Dictionary was compiled in 1914 that sense survived only locally. Normandy had a comparable unit called the vergee.

1 rood = 1,011.714106 square meters (approximately).

Sources: Wikipedia: Rood (unit); Wikipedia: Acre; Wikipedia: Rod (unit)

Related conversions

See all area units.