Iugera to Square Kilometers (iugerum to km²)

1 iugerum equals 0.0025233408 square kilometers exactly.

1 iugerum = 0.0025233408 square kilometers

How to convert iugera to square kilometers

To convert iugera to square kilometers, multiply the number of iugera by 0.0025233408. This factor is exact. To go the other way, multiply square kilometers by 396.3000162 (rounded).

square kilometers = iugera × 0.0025233408

Example: 10 iugera = 0.025233408 square kilometers.

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

Square Kilometer (km²)

Metric (SI)Current unit

One million square meters (100 hectares). Used for the area of cities, countries and lakes.

Metric land measure took a surprisingly long time to settle on the kilometer. The meter was defined in 1799, yet people initially preferred the myriameter, 10,000 meters, and the French phrase myriamètres par heure was still in print in 1802. The Netherlands adopted the kilometer in 1817 under the name mijl. Once the kilometer was established, the square kilometer followed naturally as the unit for areas too large to count comfortably in hectares or square meters.

One square kilometer is 1,000,000 square meters, or 100 hectares, about 0.3861 square miles or 247.1 acres. A useful picture comes from history: many medieval European cities were enclosed by walls around roughly a square kilometer, with Delft at about 0.9 km² and Lucca at about 1.09 km². A standard 18-hole golf course of 6,000 meters needs about 0.8 km². The symbol km² means the square of a kilometer, not a thousand square meters. The planned Square Kilometre Array radio telescope takes its name from the collecting area it aims for.

1 square kilometer = 1,000,000 square meters (exactly).

Sources: Wikipedia: Square kilometre; Wikipedia: Kilometres per hour

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