In a previous article we discussed one dimensional length units of measurement. We also reviewed two dimensional area units in another article. Therefore it’s time to take a look at three dimensional volume units of measurement.
This article will describe the volume units of measurement from the imperial, US customary and metric system. We will learn that the imperial and US customary volume units can be divided into linear, liquid and dry measurement. We will also discuss conversion to the SI unit of cubic meter.
Volume from imperial length units
Table 1 contains the three dimensional volume unit conversion factors for the imperial and US customary system. We can make a distinction between cubic inch, cubic feet, cubic yard and cubic statute mile. Also, we have already seen one dimensional length and two dimensional area unit conversion factors from previous articles. So by raising the one dimensional conversion factors to the power of three the unit conversion becomes possible.
One feet, for example, equals 12 inches. Therefore one cubic feet equals 12^3 = 1 728 cubic inches
Furthermore, a yard is the equivalent of 0,9144 meter, according to the weight and measurement act of 1963 (WMA 1963). So one cubic yard equals 0,9144^3 = 0,765 cubic meter (m3). The other SI equivalent units can also be calculated with upcoming conversion factors.
Liquid volume units of measurement
The United States and United Kingdom use liquid volume units for commercial measurement of liquids. We can hereby distinguish between fluid ounce, pint, quart and gallons.
Both countries use the same names for the the liquid units. However, these units don’t represent the same amount of liquid. Therefore it is important to indicate the unit system when using liquid volume units.
Imperial liquid volume units
Table 2 displays the imperial liquid volume units of measurement. One pint in the UK imperial system consists of twenty fluid ounces. Therefore one quart (UK) equals forty fluid ounces or two UK pint. Also, one gallon (UK) is the equivalent of 160 fluid ounce (UK), 8 UK pint or 4 UK quart.
The UK gallon is the equivalent of 4,546 082 L or 0,004 546 082 cubic meter. Therefore imperial – SI conversion factors can be defined by combining the previous internal conversion factors.
US customary liquid volume units
Table 3 displays the US customary liquid volume units of measurement. These units are different from their imperial counterparts. One US liquid gallon for example equals 3,785 L from the metric system. This is significantly different from the UK gallon, which equals metric 4,546 liter.
The oil industry also uses the barrel as a volume unit. One barrel equals 42 US liquid gallon, 168 US quart, 336 US pint or 5 376 US fluid ounces. From the preceding conversion factors the definition of the barrel follows as 159 liters.
Dry volume units of measurement
Companies from the United Kingdom don’t use dry volume units anymore. However, these units are still used for powdered materials in the United States. We can distinguish between the dry pint, dry quart, US dry gallon, peck and bushel (see table 4).
Metric volume units of measurement
Table 5 contains the commonly used volume units of measurement from the metric system. The metric volume units includes cubic millimeter, cubic centimeter, cubic decimeter, cubic meter, cubic decametre, cubic hectometer and cubic kilometer.
The metric system also makes use of the liter volume unit. One liter equals 1 cubic decimeter or 0,001 cubic meter.