Iugera to Acres (iugerum to ac)

1 iugerum equals 0.623531091 acres (rounded).

1 iugerum = 0.623531091 acres

How to convert iugera to acres

To convert iugera to acres, multiply the number of iugera by 0.623531091. The factor is rounded to 10 significant digits. To go the other way, multiply acres by 1.603769266 (rounded).

acres = iugera × 0.623531091

Example: 10 iugera = 6.23531091 acres.

Approximate value. Standards for the iugerum varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About these units

Iugerum (iugerum)

Ancient RomanHistorical unit (no longer in standard use)Approximate value

28,800 square Roman feet, about 2,523 m² (0.62 acre). The area a yoke of oxen could plow in a day.

Plowland gave the iugerum its meaning. Pliny the Elder described it as the ground a single yoke of oxen could work in a day, and the name is generally linked to the Latin iugum, a yoke, though the exact derivation is argued. Columella instead tied it to the idea of joining two actus together.

Its form was a rectangle 240 Roman feet by 120, or 28,800 square feet, which works out to about 71 by 35.5 m. With the usual 296 mm foot that gives roughly 2,523 m2, the figure used here, or close to a quarter of a hectare and 0.62 acre. A slightly different foot would move the total a little, so the figure is approximate.

The Romans built a whole land system on it. Two iugera made a heredium, the plot supposedly granted to each early citizen as heritable property, and 100 heredia made a centuria. Surveyors also split it into uncial fractions, down to the scrupulum of 100 square feet. In Gaul, half an iugerum was the arepennis, which fed into the French arpent.

1 iugerum = 2,523.3408 square meters (approximately).

Sources: Wikipedia: Jugerum; Wikipedia: Roman units of measurement

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

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