Square Chains to Hectares (sq ch to ha)

1 square chain equals 0.04046856422 hectares (rounded).

1 square chain = 0.04046856422 hectares

How to convert square chains to hectares

To convert square chains to hectares, multiply the number of square chains by 0.04046856422. The factor is rounded to 10 significant digits. To go the other way, multiply hectares by 24.71053815 (rounded).

hectares = square chains × 0.04046856422

Example: 10 square chains = 0.4046856422 hectares.

About these units

Square Chain (sq ch)

US & ImperialTraditional unit (still used in some regions)

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)

Hectare (ha)

Metric (SI)Current unit

10,000 square meters (2.471 acres). The standard unit for land and agricultural areas outside the US.

Hecto plus are: the name was coined in French, and are itself comes from the Latin area, meaning an open space. The French law of 18 Germinal, Year III (7 April 1795) defined the are as 100 square meters, and the hectare followed as 100 ares, or 10,000 square meters. The unit is therefore a product of the original French metric reforms rather than of later SI work, which is one reason its official status has always been slightly awkward.

When the SI was set up in 1960 the are was not recognized, and the hectare was classed as a non-SI unit accepted for use with it. In practice it is the standard unit for land ownership, planning and agriculture in the European Union, the United Kingdom, Canada, Australia, New Zealand and South Africa, while the United States and Myanmar stay with the acre. A hectare is a square 100 meters on each side, about the size of Trafalgar Square, and equals roughly 2.47 acres. One hundred of them make a square kilometer.

1 hectare = 10,000 square meters (exactly).

Sources: Wikipedia: Hectare; Wikipedia: Are (unit); NIST Guide to the SI, Appendix B.8: conversion factors

Related conversions

See all area units.