Square Inches to Iugera (in² to iugerum)

1 square inch equals 2.556769185×10⁻⁷ iugera (rounded).

1 square inch = 2.556769185×10⁻⁷ iugera

How to convert square inches to iugera

To convert square inches to iugera, multiply the number of square inches by 2.556769185×10⁻⁷. The factor is rounded to 10 significant digits. To go the other way, multiply iugera by 3,911,186.062 (rounded).

iugera = square inches × 2.556769185×10⁻⁷

Example: 10 square inches = 0.000002556769185 iugera.

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

Square Inch (in²)

US & ImperialCurrent unit

A square one inch on a side, exactly 6.4516 cm². Used for small parts and for pressure (pounds per square inch).

Latin uncia, one twelfth, gave English the inch, which Old English borrowed as ynce. A statute of Edward II in 1324 defined it as three barleycorns, dry and round, set end to end, and the barleycorn remained the base for centuries after 1066. The modern square inch rests on a 20th-century agreement: the United States adopted a yard of exactly 0.9144 meter on 1 July 1959, the United Kingdom followed effective 1 January 1964, and the inch became exactly 25.4 mm.

Squaring that gives exactly 6.4516 cm² for one square inch, and one square meter is about 1,550 of them. Its best-known descendant is the pound per square inch, psi, the pressure unit still used for American tires and air tanks: atmospheric pressure at sea level is about 14.7 psi, a car tire is typically inflated to around 32 psi above the surrounding air, and one psi is about 6.895 kilopascals. The square inch itself is common in the US and UK for small parts and printed material.

1 square inch = 0.00064516 square meters (exactly).

Sources: Wikipedia: Square inch; Wikipedia: Inch; Wikipedia: Pounds per square inch

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

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