Square Rods to Square Miles (sq rd to mi²)
1 square rod equals 0.000009765625 square miles exactly.
How to convert square rods to square miles
To convert square rods to square miles, multiply the number of square rods by 0.000009765625. This factor is exact. To go the other way, multiply square miles by 102,400.
square miles = square rods × 0.000009765625
Example: 10 square rods = 0.00009765625 square miles.
About these units
Square Rod (sq rd)
30.25 square yards (25.29 m²), also called a perch. 160 square rods make an acre.
Perch is the older name for this small square, and it traces back to the Roman pertica, a measuring pole. The word rod became the preferred surveyors' term in England, where land measurers carrying rods, poles or knotted cords were in demand after Henry VIII took over church estates in 1536. A square rod is the square on a rod of 16.5 feet, which works out to 272.25 square feet, or 30.25 square yards.
The odd-looking number makes sense through the acre. Edmund Gunter's 66-foot chain is four rods long, so a square chain holds 16 square rods, and ten square chains make an acre. That means 160 square rods fill an acre, and a rood holds 40. Metric equivalents are about 25.29 square meters, a little under the floor area of a small garage. Rods and perches turned up in deeds, tax records and plot descriptions for centuries, and a few English-speaking regions still quote small building plots in perches.
1 square rod = 25.29285264 square meters (exactly).
Sources: Wikipedia: Rod (unit); Wikipedia: Chain (unit); Wikipedia: Acre
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 square rods (reverse)
- Square rods to square meters
- Square rods to square kilometers
- Square rods to hectares
- Square rods to square inches
- Square rods to square feet
- Square rods to square yards
- Square rods 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.