Roods to Square Miles (rood to mi²)
1 rood equals 0.000390625 square miles exactly.
How to convert roods to square miles
To convert roods to square miles, multiply the number of roods by 0.000390625. This factor is exact. To go the other way, multiply square miles by 2,560.
square miles = roods × 0.000390625
Example: 10 roods = 0.00390625 square miles.
About these units
Rood (rood)
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)
Square Mile (mi²)
640 acres or about 2.59 km². Used for the area of cities, states and countries in the US and UK.
A thousand Roman paces, mille passus, became the mile, and under Elizabeth I Parliament fixed the statute mile at eight furlongs, or 5,280 feet, in place of the older Roman-based value. The square mile inherits that length. Its most famous use came in the United States: the Land Ordinance of 1785 started the Public Land Survey System so that western land could be surveyed and sold to pay war debts, beginning with the Seven Ranges in eastern Ohio.
In that system a section is roughly one square mile, or 640 acres, and a township is 36 sections in a square six miles on a side. One square mile is nearly 2.59 million square meters. Chicago's Midway International Airport, at about 650 acres, covers roughly 1.02 square miles. Beware the phrase mile square: a region 20 miles square has 400 square miles, but so does a rectangle 10 by 40 miles. The US survey version of the mile was retired from 1 January 2023, but the international square mile remains the unit for cities, states and countries in the US and UK.
1 square mile = 2,589,988.11 square meters (approximately).
Sources: Wikipedia: Square mile; Wikipedia: Public Land Survey System; Wikipedia: Mile
Related conversions
- Square miles to roods (reverse)
- Roods to square meters
- Roods to square kilometers
- Roods to hectares
- Roods to square inches
- Roods to square feet
- Roods to square yards
- Roods to acres
- Square meters to square miles
- Square kilometers to square miles
- Hectares to square miles
- Square inches to square miles
- Square feet to square miles
- Square yards to square miles
- Acres to square miles
- Square centimeters to square miles
- Square millimeters to square miles
- Tsubo to square miles
- Pyeong to square miles
- Rai (Thai) to square miles
See all area units.