Gunter’s measurement, sometimes Surveyor’s measurement, is a geodetic system, formerly popular in Britain and its (former) colonies. It was developped in the 17th century and is still in use today in the United States of America.

Gunter used an actual measuring chain of 100 links. These, the chain and the link, have become units of their own. Gunter’s chain is a tenth of a furlong long, i.e. 4 rods, 22 yards or 20.1168 metres. Also the rectangular area with edges of one chain and one furlong respectively is one acre, therefore the chain is sometimes called an acre-breadth. Accordingly Gunter’s link is exactly 7.92 inches or 201.168 mm. A square link makes about 62¾ square inches or exactly one hundred-thousandth of an acre and one ten-thousandth of one square chain.

In some places other lengths have been used, for example 8.928 inches (ca. 0.227 m) in Scotland and 10.08 inches (ca. 0.256 m) in Ireland.

Chain is usually abbreviated as 'ch.', whereas link becomes either 'l.', 'li.' or 'lnk.'.

Another English, similar system of about the same age but lesser popularity is Ramsden’s or the engineer’s system, where the chain consists also of 100 links, each one foot (0.3048 m) long. The even less common Rathborn system, also from the 17th century, is based on a chain of two rods (33 feet, 10.0584 m) length, which consists of 100 links, too (1.98 inches, 50.292 mm each), which are called seconds (″), ten of which make a prime (′, 19.8 inches, 0.503 m).

See also: Chain (unit), Chain