British Weights & Measures: The Imperial System

This sytem served us well for about 2000 years, until superceded by the SI (metric) system in 1971. Parts, such as the statute mile and the pint, are still in use. However, the decision to re-draw Admiralty charts, retaining nautical miles, derived from 1/60 degree of latitude on the earth's surface, with depth of water in metres was illogical.
Arguably, a system of length and money based on '12', has greater flexibility than one based on '10'.
This page helps to keep the system alive and kicking strongly.

• Linear Measure:

  
  On Land:
  12 inches = 1 foot.
  3 feet = 1 yard.
  5.1/2 yards = 1 Rod, (pole or perch)
  22 yards = 1 chain, (cricket pitch).
  10 chains or 40 poles = 1 furlong.
  8 furlongs = 1 statute mile, (duo millia passuum or 2000 Roman paces).
  And At Sea:
  200 yards = 1 cable (horizontal distance at sea).
  10 cables = 1 nautical mile, (2000 yards)
  60 nautical miles = 1 degree latitude on The Earth's surface.
  1 fathom water depth = 6 feet.

  
  

• Area:

  
  144 square inches = 1 square foot.
  9 square feet = 1 square yard.
  1210 square yards = 1 rood.
  4 roods = 1 acre, (4840 square yards).
  640 acres = 1 square mile

  
  

• Liquids & Volumes:

  
  60 minims = 1 fluid drachm.
  8 fluid drachms = 1 fluid ounce.
  20 fluid ounces = 1 pint
  1/2 pint = 1 gill (North of England measure)= 1 noggin.
  4 gills = 1 pint.
  2 pints = 1 quart.
  4 quarts = 1 gallon.
  2 gallons = 1 peck.
  4 pecks = 1 bushell
  8 bushells = 1 quarter.
  63 gallons = 1 hogshead.
  84 gallons = 1 puncheon.
  2 hogsheads = 1 pipe.
  2 pipes = 1 tun.

  
  

• Weights:

  
  1 pennyweight (dwt) = 1/20 ounce (Troy).
  16 drachms, (avoirdupois) = 1 ounce.
  8 drachms, (apothecaries measure) = 1 ounce.
  16 ounces = 1 pound (lb. = libra).
  8 pounds = 1 customary stone, (butchered meat).
  14 pounds = 1 legal stone, (horseman's weight).
  112 pounds = 1 hundredweight, (cwt).
  20 hundredweights = 1 ton.
  

  
  

• British Money:

  
  1 farthing = one quarter of a penny.
  2 farthings = 1 ha'penny.
  2 ha'penny = 1 penny(d.= denarius).
  12 pence = 1 shilling.
  240 pence = 1 pound (£)
  2 shillings & 6 pence = Half a Crown
  5 shillings = One Crown
  20 shillings = 1 pound (£) sterling = exact weight of pure metal.
  1 sovereign = a £1 gold coin.
  21 shillings (£1-1-0) = 1 guineau, (first coined for trade in West Afrca)
  

  
  farthings, ha'pennies and pennies were called "coppers" because they were originally coined in copper alloy, and 240 pennies weighed a pound.

• Twelve Inch Notes:
  This is an aide memoir for helping to solve difficult problems and crossword puzzles, starting and resolving arguments.
  Contributions and further suggestions welcome; but inclusion cannot always be guaranteed.