Most of the US
system of measurements is the same as that for the UK. The biggest differences
to be noted are in Capacity which has both liquid and dry measures as well as
being based on a different standard - the US liquid gallon is smaller than the
UK gallon. There is also a measurement known at the US survey foot. It is
gradually being phased out as the maps and land plans are re-drawn under
metrication. (The changeover is being made by putting 39.37 US survey feet = 12
metres) Length Area
12 inches = 1 foot 144 sq. inches = 1 square foot
3 feet = 1 yard 9 sq. feet = 1 square yard
220 yards = 1 furlong 4840 sq. yards = 1 acre
8 furlongs = 1 mile 640 acres = 1 square mile
5280 feet = 1 mile 1 sq.mile = 1 section
1760 yards = 1 mile 36 sections = 1 township
Volume
1728 cu. inches = 1 cubic foot
27 cu. feet = 1 cubic yard
Capacity (Dry) Capacity (Liquid)
16 fluid ounces = 1 pint
2 pints = 1 quart 4 gills = 1 pint
8 quarts = 1 peck 2 pints = 1 quart
4 pecks = 1 bushel 4 quarts = 1 gallon (8 pints)
Mass
437.5 grains = 1 ounce Troy Weights
16 ounces = 1 pound (7000 grains) 24 grains = 1 pennyweight
14 pounds = 1 stone 20 pennyweights = 1 ounce (480 grains)
100 pounds = 1 hundredweight [cwt] 12 ounces = 1 pound (5760 grains)
20 cwt = 1 ton (2000 pounds)
Apothecaries' Measures Apothecaries' Weights
60 minims = 1 fl.dram 20 grains = 1 scruple
8 fl.drams = 1 fl.ounce 3 scruples = 1 dram
16 fl.ounces = 1 pint 8 drams = 1 ounce (480 grains)
12 ounces = 1 pound (5760 grains)
As with the UK system these measures were originally defined by physical
standard measures - the yard, the pound, the gallon and the bushel.They are now
all defined by reference to the S I measures of the metre, the kilogram and the
litre. These equivalent measures are exact.
1 yard = 0.9144 metres - same as UK
1 pound = 0.453 592 37 kilograms -
same as UK
1 gallon (liquid) = 3.785 411 784 litres
1 bushel = 35.239 070
166 88 litres
Note particularly that the US gallon is a different size to
the UK gallon so that NO liquid measures of the same name are the same size in
the US and UK systems.
Also that the ton(US) is 2000 pounds while a ton(UK)
is 2240 pounds. These are also referred to as a short ton and long ton
respectively.
Note than in matters concerned with land measurements, for the
most accurate work, it is necessary to establish whether the US survey measures
are being used or not.
