Square Chains to Square Kilometers (sq ch to km²)
1 square chain equals 0.0004046856422 square kilometers (rounded).
How to convert square chains to square kilometers
To convert square chains to square kilometers, multiply the number of square chains by 0.0004046856422. The factor is rounded to 10 significant digits. To go the other way, multiply square kilometers by 2,471.053815 (rounded).
square kilometers = square chains × 0.0004046856422
Example: 10 square chains = 0.004046856422 square kilometers.
About these units
Square Chain (sq ch)
484 square yards (404.69 m²), one tenth of an acre. A surveying unit.
Surveyors rather than farmers gave this unit its shape. In 1620 the English clergyman and mathematician Edmund Gunter devised a measuring chain of 100 links that was 66 feet long, and by 1675 it was in wide use. A square chain, 66 feet by 66 feet, covers 4,356 square feet, or 484 square yards. The convenient result is that ten of them make exactly one acre, so a plot measured in chains could be turned into acres by moving a decimal point.
That arithmetic was the reason the US adopted the chain. A report by Thomas Jefferson in 1784 led to the Land Ordinance of 1785, which required the chain for surveying the public lands, and many American property lines still trace back to chain measurements. In metric terms a square chain is about 404.69 square meters. The linear chain remains in niche use, for example in railway milepost distances in Britain, in wildfire spread rates in the United States, and as the length of a cricket pitch.
1 square chain = 404.6856422 square meters (approximately).
Sources: Wikipedia: Chain (unit); Wikipedia: Acre; Wikipedia: Rod (unit)
Square Kilometer (km²)
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
Related conversions
- Square kilometers to square chains (reverse)
- Square chains to square meters
- Square chains to hectares
- Square chains to square inches
- Square chains to square feet
- Square chains to square yards
- Square chains to acres
- Square chains to square miles
- Square meters to square kilometers
- Hectares to square kilometers
- Square inches to square kilometers
- Square feet to square kilometers
- Square yards to square kilometers
- Acres to square kilometers
- Square miles to square kilometers
- Square centimeters to square kilometers
- Square millimeters to square kilometers
- Tsubo to square kilometers
- Pyeong to square kilometers
- Rai (Thai) to square kilometers
See all area units.