Perch (unit of measure)

Perch (unit of measure)

A perch is as a unit of measurement used for length, area, and volume in a number of different systems of measurement. Its name derives from the Ancient Roman unit, the "pertica".


The word perch is from the French perche, derived from the Latin pertica, meaning a pole or staff. [Websters 20th Century Unabridged Dictionary, ISBN 0-529-04852-3] [Wictionary, Perch] Originating in Roman antiquity, it spread with the Roman Empire and was likely re-introduced to England with the Norman Conquest of 1066. In the Roman Empire, France and England, it also could mean area (square perches), and among operative masons of the middle ages, volume.


The perch as a lineal measure in Rome, was convert|10|ft|m, and in France varied from 10 feet (perche romanie) to 22 feet (perche d'arpent - apparently 1/10th of "the range of an arrow". - about 220 feet). To confuse matters more, by ancient Roman definition, an arpent equaled 120 Roman feet.

In England, the perch was officially discouraged in favor of the rod as early as the 15th century [Encyclopedia Britannica, English measure] , however local customs maintained its use. While the rod as a survey measure was standardized by Edmund Gunter in England in 1607 as 1/4 of a chain (of 66 feet), or 16 1/2 feet (5 1/2 yards) in length, in the 13th century perches were recorded in lengths of 18, 20, 22 and convert|24|ft|m; and even as late as 1820, a House of Commons report notes lengths of 16.5, 18, 21, 24, and even convert|25|ft|m [United Kingdom. House of Commons Report (Second) of Commissioners to Consider the Subject of Weights and Measures, 13 July 1820. Parliamentary Papers 1820. (HC314) Pages 473-512.] . In Ireland, a perch was standardized at convert|21|ft|m, making an Irish chain, furlong and mile proportionately longer by 27.27% than the "standard" English measure. [ [ Units: P ] ]


As a unit of area, a square perch (the perch being standardized to equal 16.5 feet) is equal to a square rod, 30¼ square yards, 25.29 square metres or convert|0.00625|acre|m2. There are 40 square perches to a rood, 160 square perches to an acre This unit was usually referred to as a "perch" or "pole" even though "square perch" and "square pole" were the more precise terms. Confusingly, "rod" was used as a unit of area but it meant a rood.

Obviously, regional interpretations of perch would yield different results.


Used in stone or brick masonry, a perch has a volume of one perch length (nominally 16.5 feet), by 1 and one half foot high, by convert|1|ft|m|sing=on in width, for a volume (nominal) of convert|24.75|cuft|m3.

ee also

*Systems of measurement
*History of measurement


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Perch (disambiguation) — Perch may refer to:*Perch (plural perches), a rod, or branch of a tree etc, used as a roost by a bird *The USS Perch , one of two submarines in the United States Navy **USS Perch (SS 176) **USS Perch (SS 313)*Perch, an antique unit of measure of… …   Wikipedia

  • perch — perch1 [pʉrch] n. pl. perch or perches [ME perche < OFr < L perca < Gr perkē < IE base * perk̑ , speckled, colorful > Ger farbe, color, OE forn, trout] 1. any of a family (Percidae) of small, spiny finned, freshwater, percoid food… …   English World dictionary

  • perch — {{11}}perch (n.1) where a bird rests, late 13c., a pole, rod, stick, stake, from O.Fr. perche unit of linear measurement (5.5 yards), also measuring rod, pole, bar used to measure this length (13c.), from L. pertica pole, long staff, measuring… …   Etymology dictionary

  • measure — Synonyms and related words: A, Alexandrine, Spenserian stanza, Stabreim, a, accent, accent mark, accentuation, accommodate, accommodation, accomplished fact, accomplishment, accord, achievement, acreage, act, acta, action, ad hoc measure, adapt,… …   Moby Thesaurus

  • Unit of length — A unit of length is a way of measuring length or distance.Common units of length in the International System of Units (SI) are: * metre and its multiples, such as centimetre or kilometre Non SI units of length include: * fermi (fm) (= 1… …   Wikipedia

  • perch — A unit of lineal measure, the same as a rod. A unit of cubic measure for stone, equalling in most jurisdictions twenty four and three fourths cubic feet. Baldin Quarry Co. v Clements, 38 Ohio St 587. A roost for a bird. A kind of fish …   Ballentine's law dictionary

  • English unit — is the American name for a unit in one of a number of systems of units of measurement, some obsolete, and some still in use in present day USA, the UK, and elsewhere. The modern United States customary units system as a whole is not, and has… …   Wikipedia

  • linear measure — noun a unit of measurement of length • Syn: ↑linear unit • Hypernyms: ↑unit of measurement, ↑unit • Hyponyms: ↑long measure, ↑astronomy unit, ↑ …   Useful english dictionary

  • linear unit — noun a unit of measurement of length • Syn: ↑linear measure • Hypernyms: ↑unit of measurement, ↑unit • Hyponyms: ↑long measure, ↑astronomy unit, ↑ …   Useful english dictionary

  • area unit — noun a system of units used to measure areas • Syn: ↑square measure • Hypernyms: ↑unit of measurement, ↑unit • Hyponyms: ↑square inch, ↑sq in, ↑s …   Useful english dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”