perch [English]


In the Anglo-Saxon and English-speaking world, 9th century – present, a unit of length typically used in measuring land. link to a table of English units of length The usual value is 5½ yards = 16½ feet (= 5.0292 meters), which was made the legal value no later than the early 14th century:

Statutum de Admensuratione Terre.

And Be it Remembered, That the Iron Yard of our Lord the King, containeth three Feet and no more. And a Foot ought to contain Twelve Inches, by the right measure of this Yard measured; to wit, The Thirty-sixth Part of this Yard rightly measured maketh one Inch, neither more nor less. And Five Yards and a half make one Perch, that is Sixteen Feet and a half, measured by the aforesaid Iron Yard of our Lord the King.

Statutes of the Realm, vol. I, page 206.

The perch was abolished in the United Kingdom by the Weights and Measures Act of 1963. It survives in the United States.

The perch is also called, in many contexts, a rod or pole, and even a goad. The word “rod” is probably from a Germanic language, some think Norse, while perch is from the French, which is from the Latin pertica, and would have come to Britain with the Norman invaders. These two words for basically the same thing have persisted to the present day.

Grierson has suggested that the Saxon gyrd, or rod, was the combined length of 20 average, actual, human feet.1

The size of the perch (or rod) was constrained by its use in defining the acre, which was a work unit of land: as much as a team of oxen could plow in a day. The length of the acre (the furrow-long, or furlong) is as far as the team can plow without needing a breather. The width was the number of furrows that could be plowed before the oxen had to be put out to pasture for the day. At least as early as the 8th century an acre was a piece of land 40 perches long by 4 perches wide. 

Values of 5½ yards to a perch and 16½ feet to a perch are very strange conversion factors for a key unit in land measure. See the explanation in mile. The most plausible explanation may be found in 16-foot perch, below.

However, perches from 9 feet to 25 feet are known to have been used. The shorter values occur in connection with farmland; longer values occur in cities and in measuring forest land. The confusion this led to can be felt in the writing of an anonymous 14th century author:

How the Land Ought to be Measured

Because acres are not all of one measure, for in some countries they measure by the perch of eighteen feet, and in some by the perch of twenty feet, and in some by the perch of twenty-two feet, and in some by the perch of twenty-four feet, know that the acre which is measured by the perch of eighteen feet makes an acre and a rood, and the sixteenth of a rood, of the perch of sixteen feet, and four acres make five acres and a quarter of a rood, and eight acres make ten acres and a half rood, and sixteen acres make twenty acres and a rood. And the acre which is measured by the perch of twenty feet makes one acre and a half and the quarter of a rood, and four acres make six acres and a rood, and eight acres make twelve acres and a half, and sixteen acres are twenty-five acres. And the acre which is measured by the perch of twenty-two feet makes one acre and a half, and a rood and a half and the sixteenth of a rood, and four acres make seven and a half and quarter of a rood, and eight acres make fifteen acres and a half rood, and sixteen acres make thirty acres and a rood. And the acre which is measured by the perch of twenty-four feet makes two acres and a rood, and four acres make nine acres.

Hosebonderie. in
Elizabeth Lemond, editor and translator.
Walter of Henley's Husbandry, together with an anonymous Husbandry, Seneschaucie and Robert Grosseteste's Rules.
London: Longmans, Green, and Co., 1890.
Page 69. See page xli. 16 foot pole by 14th century "This must have been a difficult sum to work out, and it is to the author's credit that his arithmetic is correct."

1. R. A. Connor.
Chapter 3. The Saxon Gyrd, the Rod and the Acre.
In The Weights and Measures of England.
London: HMSO, 1987.



Byen sauet ke vne coture deyt estre de quarante perches de long, e iiij perches de lee. E la perche le rey est de xvi pez e demi e adonc est le acre de lxvj pyez de leyse.

You know well that a furlong ought to be forty perches long, and four perches wide. And the king's perch is sixteen feet and a half; then an acre is sixty-six feet in width.

Elizabeth Lamonde.
Walter of Henley's Husbandry, together with an anonymous husbandry, seneschaucie and Robert Grosseteste's Rules.
London: Longmans, Green, and Co., 1890.
Pages 8 and 9. We have altered the translation a bit. Lamonde renders “coture” as "furlong". 
Walter of Henley is thought to have written in the late 13th century.


First in generall, Land is measured by a Pole, Perch, or Rod, which is usually 16 feet, and an half long; yet in some places they use a Pole of 18 feet, especially for Wood-lands.

Henry Phillippes.
The Purchasers Pattern. 2nd ed., corrected and enlarged.
London: Printed for R. & W. Leybourn, for T. Pierrepont..., 1654.
Page 159.

Some perches with values other than 5½ yards, 16½ feet:

Rod of 9 feet 3 inches

Dumfriesshire, Scotland.1

1. Second Report of the Commissioners, 1820. Appendix page 26.

Perch of 12 feet

Tenant-right; court measure

Perch of 13½ feet

Mr. Bennet of Glan yr Afon, Llanidloes, at the instance of Mr. Evan Powell, also of Llandiloes, was good enough to collect for me, in the year 1887, some information as to the land-measures of Montgomeryshire. In the prosecution of his inquiries he called upon Richard Rees of Llawr y Glyn, then eighty-two years of age, who many years ago used to do all the tori bettin, or sod-paring work, in that neighbourhood. When he told Richard Rees on what business he was come, the old man, first of all, got out of his wain-house his measuring stick, which he called “a quart rod”, and then described its length: “Pedair llathen a haner yn exact” (exactly four and a half yards), said he. Well, there is “the rod of Hywel Dda”, containing thirteen and a half square feet, or eighteen feet of nine inches. The old man finally took Mr. Bennett into the field, and measuring on the ground twenty times the length of the rod in one direction, and then, at right angles, eight times its length, said “Dyna i chwi stang o dir” (there's a stang of land for you). 

Alfred Neobard Palmer.
Notes on Ancient Welsh Measures of Land .
Archaeologia Cambrensis. Fifth Series. Vol. 13, no. 49. (January 1896)
Pages 3 and 4.

Lug or Goad of 15 feet, 1 inch

“Lug or Lugg, Dorsetshire [England]: Of land, 15 feet and an inch; called also Goad, used instead of a pole of 16½”1

1. Second Report of the Commissioners, 1820. Appendix page 23.

Rod of 16 feet

Various citations from the 13th century on. This may represent a survival of the rod as it was brought to Britain by Germanic invaders. The feet in question were probably originally Rhineland Fuss, not statute feet, which makes a measure that corresponds to the Ruthe of 16 Rhineland Fuss found in parts of German-speaking Europe. In fact, 16 Rhineland Fuss corresponds in length to 16½ statute feet, the ultimate legal value of the English perch.

Fall or rod of 18½ feet

In Scotland, the fall, raip (rope) or rod = 6 ells, each of 37 inches. Earlier rod of 20 feet in cities.

The rude off lande in baronyse sal conten vj elne that is to say xviij fut off a mydlyn mane, the rude off the land in the burghe mesurit off a midlyng mane sal be xx fut.

The rod of land in the countryside shall contain 6 ells, that is to say, 18 [natural] feet of a middling man. The rod of land in the burgh measured by a middling man shall be 20 feet.

T. Thomson and C. Innes, editors.
The Acts of the Parliament of Scotland.
Edinburgh: 1814-1875.
Volume I, page 751. Fragmenta … Collecta no. 15.

Perch of 21 feet

In Ireland, = 1⁄320 of an Irish mile. Also called an Erse pole.

“...the Irish perch or pole is 7 yards, and that of England only 5½. Hence 11 Irish miles are equal to 14 English miles.”

Kelly, 1835, page 195.

In Sherwood Forest “21 foot go to the Pearch, the foot there being 18 Inches long, the measure of which foot was on the Chancel-wall of Edenstow, and in the church of St. Mary in Nottingham”1 Sometimes called the “forest pole.”

1. Worlidge, 1704.


The square perch was sometimes called a perch, for example in Ireland.


In Devonshire, “of stone work, 16½ feet in length, 1 in height, and 22 inches in thickness. of cob work, 18 feet in length, 1 in height, and 2 in thickness.”1

In Herefordshire, United Kingdom, a perch of walling = 16½ feet1,2; a perch of ditching = 21 feet.2  Of fencing, 21 feet.1

Like the perch itself, the perch of masonry was different in Ireland. See source 1 below.

In the United States, for masonry work, as late as the 20th century, 24¾ cubic feet, or a section of wall 16½ feet long (1 perch), 1½ feet thick, and 1 foot high. Sometimes considered to be 25 cubic feet.3 The conventions for estimating and billing for a masonry job varied by region, but some trade customs were universal: the estimate was based on the surface of the walls (which meant masonry in the corners was knowingly counted twice), and no deductions were made for any opening less than three feet wide.

In some western states of the United States, the perch for rubble work was 16½ cubic feet.4

1. Second Report of the Commissioners, 1820. Appendix page 26.

2. Worlidge, 1704.

3. For example, in legislation in Iowa (Code, 1924, ch. 161, sec. 3243), North Dakota (Comp. Laws. 1913, Vol. 1, Art. 59, sec. 3008), Ohio (Gen. Code, 1921, Throckmorton, ch. 32, sec. 6408), Oklahoma (Comp. Stats. 1921, Vol. 2, ch. 92, Art. 1, sec. 11187), and South Dakota (Rev. Code, 1919, Vol 2, Part 22, ch. 8, Art 1, sec. 10374).

4. McClurg/Shoemaker.
The Building Estimator's Reference Handbook. 17th edition.
Chicago: Frank R. Walker Company, 1970.

Page 1644.



In Builders’ work, 21 feet long [that is, 1 Irish perch-ed.], 1 foot high, and 18 inches thick, make 1 Perch of Mason’s work. 21 Feet long, 1 foot high, and 9 inches thick, make 1 Perch of Bricklayers’ work. So that 31½ solid feet make 1 Perch of Masonry, and 15¾ solid feet make 1 Perch of Brick work.

Edward Wakefield.
An Account of Ireland, statistical and political.
London: Printed for Longman, Hurst, Rees, Orme, and Brown, 1812.
Volume 2, page 197. Masons and bricklayers were paid by the perch, not the day: in Kilkenny in 1790, 1 shilling per perch (page 204).


 A perch of masonry work, or stone, is hereby declared to consist of sixteen and one-half feet cubic measure.

 Laws of the State of New Mexico, Statutes, 1915, ch. 116, section 5836.
Similar laws existed in Colorado (1921) and Idaho (1883).


2. A perch of stone shall contain, when measured in the wall, twenty-four and three-quarters cubic feet; when measured in square piles on the ground, twenty-seven cubic feet; when measured in cars, thirty-one and one-half cubic feet.  All stone to be measured in the wall when practicable.

Laws of the State of Delaware, Revised Code, 1915, ch. 82, section 2931.


The Lack of Uniformity in Measuring Stone.

Owing to the variety of uses to which stone is put, there is no regular unit of measurement employed by the quarryman, the stone being sold by the cubic yard, cubic foot, ton, cord, perch, rod, square foot, square yard, square, or other unit. Building and monumental stone, especially the dressed product, is usually sold by the cubic foot or the cubic yard, although this unit varies with the class of stone and with the locality. A large quantity of the rough stone is sold by the perch, cord, or ton. Rubble and riprap, including stone for such heavy masonry as breakwater and jetty work, are generally sold by the cord or ton. Fluxing stone and stone for chemical use is sold by either the long or the short ton. Flagstone and curbstone are sold by the square yard or the square foot, the thickness being variable and dependent on the orders received. Crushed stone is reported as sold by the cubic yard or ton, the short ton being more generally used.

The perch is legally defined in many older states as 24¾ cubic feet; in some states, and even within a single state, it varies from 16½ through 20, 22, 25 to 27 cubic feet; and in others it is defined as equivalent to 2,200, 2,500, 2,700, 2,800, and 3,000 pounds. The cord in some states is measured in feet—for instance, 128 cubic feet in the quarry or 100 feet in the wall; in others it denotes weight and is variously defined as equivalent to 11,000, 12,000, 12,500, and 13,000 pounds. The weight of a cubic yard of crushed stone varies from 2,300 to 3,000 pounds, the average weight being about 2,500 pounds. In certain localities this crushed stone is sold by the "square" of 100 square feet by 1 foot, or 100 cubic feet. It is also of interest to note the selling of crushed stone by the bushel, 21½ bushels representing a cubic yard of about 2,700 pounds.

[Editor's Note.-The above quotation from "Stone in 1915" (2A1d) emphasizes the necessity for concerted action in bringing about, if possible, uniform methods of measurement for stone in all parts of the country. This matter will be brought to the attention of the Institute's Committee on Materials and Methods in the hope that through its subcommittes in the various Chapters some line of action may be determined upon to assist in bringing about standardization.]

Quoted from Journal of the American Institute of Architects, vol. 5, no. 2, page 85 (February 1917). "Stone in 1915" is a section of Mineral Resources of the United States.

home| units index| search| to contact Sizes drawing of envelope| acknowledgements| help|


terms of use