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.
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 |
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.
| 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 × 10-1 | 0.720571 |
| tablespoon | 9.02344 × 10-1 | tablespoonful | 8.66938 × 10-1 | 0.960762 |
| 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 Dry | cubic inches | British Imperial | cubic inches | Brit ÷ Amer |
|---|---|---|---|---|
| pint | 3.36003 × 10+1 | pint | 3.46775 × 10+1 | 1.03206 |
| quart | 6.72006 × 10+1 | quart | 6.93550 × 10+1 | 1.03206 |
| peck | 5.37605 × 10+2 | peck | 5.54840 × 10+2 | 1.03206 |
| bushel | 2.15042 × 10+3 | bushel | 2.21936 × 10+3 | 1.03206 |
| American Fluid | cubic inches | American Dry | cubic inches | Dry ÷ Fluid |
|---|---|---|---|---|
| pint | 2.88750 × 10+1 | pint | 3.36003 × 10+1 | 1.16365 |
| quart | 5.77500 × 10+1 | quart | 6.72006 × 10+1 | 1.16365 |