Some Traditional British and American Units of Volume.
Version of November 27, 2001.
Dave Barber's other pages.

These British measures are as codified in the British Imperial Standards Act of 1824; to a large extent they were taken from earlier English tradition. The standards of Ireland and Wales were officially abolished at that time, and those of Scotland in 1706. However, some weights and measures lingered in isolated areas as much as a century after statutory abolition.

As the United States became independent in 1776, its standards derive from the English in the era before the Imperial Act. Moreover, in the mid-twentieth century the United Kingdom changed to the Metric system, again with no effect on the United States.

British Measures of Volume

The fundamental unit of volume is the gallon, which is defined as the volume of 10 avoirdupois pounds of water at 62 fahrenheit degrees. Because the gallon contains 160 fluid ounces, and 10 avoirdupois pounds contain 160 avoirdupois ounces, it stands that one fluid ounce of water will weigh one avoirdupois ounce. The reader is cautioned that one fluid ounce of some other substance may have quite a different weight. For instance, one fluid ounce of helium weighs less than one avoirdupois ounce. Meanwhile, one fluid ounce of lead weights more than one avoirdupois ounce.

The following table amalgamates the capacity and culinary measures, as well as those apothecary measures pertaining to volume.

apo cul cap unit cubic inches liters relation
+     minim 3.61224 × 10-3 5.91940 × 10-5
+ +   fluid dram 2.16734 × 10-1 3.55164 × 10-3 60 minims
+   teaspoonful 2.16734 × 10-1 3.55164 × 10-3 1 fluid dram
+   dessertspoonful 4.33469 × 10-1 7.10328 × 10-3 2 teaspoonfuls
+   tablespoonful 8.66938 × 10-1 1.42066 × 10-2 2 dessertspoonfuls
+     fluid ounce 1.73388 2.84131 × 10-2 2 tablespoonfuls
+   wineglassful 4.33469 7.10328 × 10-2 5 tablespoonfuls
+ gill 8.66938 1.42066 × 10-1 2 wineglassfuls
+   teacupful 8.66938 1.42066 × 10-1 1 gill
+   tumblerful 1.73388 × 10+1 2.84131 × 10-1 2 teacupfuls
+   + pint 3.46775 × 10+1 5.68262 × 10-1 2 tumblerfuls
+ quart 6.93550 × 10+1 1.13652 2 pints
+   + gallon 2.77420 × 10+2 4.54610 4 quarts
+ peck 5.54840 × 10+2 9.09220 2 gallons
+ bushel 2.21936 × 10+3 3.63688 × 10+1 4 pecks
+ quarter 1.77549 × 10+4 2.90950 × 10+2 8 bushels
+ chalder 7.98970 × 10+4 1.30928 × 10+3 36 bushels

American Measures of Volume

Dry Measure

The American bushel comes from the English dry "Winchester" bushel, defined as the volume of a cylinder 18.5 inches in diameter and 8 inches high.

unit cubic inches liters relation
pint 3.66003 × 10+1 5.50611 × 10-1
quart 6.72006 × 10+1 1.10122 2 pints
peck 5.37605 × 10+2 8.80977 8 quarts
bushel 2.15042 × 10+3 3.52391 × 10+1 4 pecks
barrel 7.05607 × 10+3 1.15628 × 10+2 105 quarts

Liquid Measure

Despite the word "liquid", these measures are in the kitchen used for small quantities of both wet and dry ingredients; this is underscored by the fact that the smallest "dry" measure is a pint. This gallon is taken from the English wine gallon, deemed as the volume of a cylinder seven inches in diameter and six inches in height. This calculates to 230.907 cubic inches, but the figure has been standardized to 231 precisely.

unit cubic inches liters relation
minim 3.75977 × 10-3 6.16115 × 10-5
fluid dram 2.25586 × 10-1 3.69669 × 10-3 60 minims
teaspoon 3.00781 × 10-1 4.92892 × 10-3 80 minims
tablespoon 9.02344 × 10-1 1.47868 × 10-2 3 teaspoons
fluid ounce 1.80469 2.95735 × 10-2 2 tablespoons
gill 7.21875 1.18294 × 10-1 4 fluid ounces
cup 1.44375 × 10+1 2.36588 × 10-1 2 gills
pint 2.88750 × 10+1 4.73176 × 10-1 2 cups
quart 5.77500 × 10+1 9.46353 × 10-1 2 pints
gallon 2.31000 × 10+2 3.78541 4 quarts

The fluid barrel is of 42 gallons for petroleum, 31 gallons for wine, and 31.5 gallons for most other liquids.

Ratios of Some Volume Units with Similar Names

American Fluid cubic inches British Imperial cubic inches Brit ÷ Amer
minim 3.75977 × 10-3 minim 3.61220 × 10-3 0.960762
fluid dram 2.25586 × 10-1 fluid dram 2.16734 × 10-1 0.960762
teaspoon 3.00781 × 10-1 teaspoonful 2.16734 × 10-10.720571
tablespoon 9.02344 × 10-1 tablespoonful 8.66938 × 10-10.960762
fluid ounce 1.80469 fluid ounce 1.73388 0.960762
gill 7.21875 gill 8.66938 1.20095
cup 1.44375 × 10+1 tumblerful 1.73388 × 10+1 1.20095
pint 2.88750 × 10+1 pint 3.46775 × 10+1 1.20095
quart 5.77500 × 10+1 quart 6.93550 × 10+1 1.20095
gallon 2.31000 × 10+2 gallon 2.77420 × 10+2 1.20095

American Drycubic inches British Imperialcubic inchesBrit ÷ Amer
pint 3.36003 × 10+1 pint 3.46775 × 10+11.03206
quart 6.72006 × 10+1 quart 6.93550 × 10+11.03206
peck 5.37605 × 10+2 peck 5.54840 × 10+21.03206
bushel2.15042 × 10+3 bushel2.21936 × 10+31.03206

American Fluidcubic inches American Drycubic inchesDry ÷ Fluid
pint 2.88750 × 10+1 pint 3.36003 × 10+11.16365
quart5.77500 × 10+1 quart6.72006 × 10+11.16365