The U S System of Measurements

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 redrawn under metrication. (The changeover is being made by putting 39.37 US survey feet = 12 meters)

	 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 meter, the kilogram and the liter. These equivalent measures are exact.

1 yard = 0.9144 meters - same as UK
1 pound = 0.453 592 37 kilograms - same as UK
1 gallon (liquid) = 3.785 411 784 liters
1 bushel = 35.239 070 166 88 liters

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.