Imperial Lengths and Areas

Although officially only used since 1824, there was 141 years until Great Britain changed to the metric system in 1965. Though, nearly 60 years ago, imperial units still remain in surprisingly widespread use amongst the general public, not least in relation to roads.

Length:

Inch [2.54 cm]
Link = 7.92 inches
Foot = 12 inches [30.48 cm]
Yard = 3 feet [91.44 cm]
Rod, Pole or Perch = 25 links = 5½ yards [about 5 metres]
Chain = 22 yards = 66 feet = 100 Links [length of a cricket wicket, about 20 metres]
Furlong = 10 chains = 220 yards [length of a furrow, about 200 metres]
Mile = 8 furlongs = 1760 yards = 5280 feet [a thousand Roman paces (a Roman ‘pace’ was actually 2 paces: left, right) – about 1600 metres]

Area:

Sq. foot = 144 sq. inches
Sq. yard = 9 sq. feet = 1296 sq. inches [0.836 sq. metre]
Sq. Pole = 30¼ sq. yards [often simply referred to as a Pole or Perch in land measurement]
Rood = ¼ acre = 1,210 sq. yards = 40 sq. poles
Acre = 4 roods = 10 sq. chains = 4840 sq. yards = Statute acre [0.40 hectare] [e.g. a good-sized football pitch – but note that a Customary (or Saxon) acre was different, and that Scottish and Irish acres were different again]
Virgate = 30 acres [but varied in different districts – also called yardland]
Hide = 4 virgates [but really denoted the amount of land sufficient to support a family, and varied according to the locality or quality of the land]Sq. mile = 640 acres [259 hectares = 2.59 Sq. Km]

Capacity [note, equivalents are for British Imperial measures]:

1 pint = 4 gills = 20 fluid ounces [0.568 litre]
1 quart = 2 pints [1.136 litre]
1 gallon = 4 quarts = 8 pints [4.546 litres]
1 peck = 2 gallons
1 bushel = 4 pecks = 8 gallons

Weight:

1 ounce (oz) = 16 drams
1 pound (lb) = 16 oz [0.454 kg]
1 stone = 14 lb
1 quarter = 28 lb
1 hundredweight (cwt) = 4 quarters = 112 lb
1 ton = 20 cwt = 2240 lb [1.016 tonne]

Money: (pre-Feb 1971)

1 penny (d) = 4 farthings [d = denarius, a Roman coin, translated to ‘penny’ in the Bible]
1 shilling (s) = 12 pence/pennies [converted in 1971 to 5 new pence]
1 crown = 5 shillings
1 pound (£) = 4 crowns = 20 shillings
1 guinea = 21 shillings