Mass Measurements in the British Imperial and US Customary Systems
What is a System of Measurement?
Systems of measurements are different types of measurements consisting of units and rules to govern them. These have been historically changed, regulated, and well defined to assist us in scientific and commercial trade purposes, especially between continents and nations. Major systems of measurements are,
- International System of Units (SI), also called the metric system.
- The British imperial system.
- The United States customary system.
The British Imperial and US Customary Units
Both the British imperial units and the US customary units derive from earlier English units used in England up to 1826, which evolved as a combination of the Anglo-Saxon and Roman systems of units.
The British imperial units are still used for some applications in the United Kingdom but have been mostly replaced by the metric system. On the other hand, the United States still uses the US customary units as their main system of measurement.
Though the British imperial and US customary systems are related to each other, there are a few differences between them.
The systems of measurements of mass and weight in the British imperial and the US customary units are,
- The Avoirdupois system.
- The Troy system.
- The Apothecaries' system.
The Avoirdupois system is the most commonly used while the Troy system is used for weighing precious metals. And the Apothecaries' system was used in pharmacology and has now been replaced by the metric system.
Units of Mass in the British Imperial and US Customary Systems
To find out how heavy something is, you need to measure its weight. The most common units of mass in the British imperial units and the US customary units are,
- Ounce
- Pounds
- Tons
Ounces (oz)
The first one is the ounce. The two most common types of ounces used in mass measurements are,
- Avoirdupois Ounce
- Troy Ounce
Avoirdupois ounce
The avoirdupois ounce, abbreviated as "oz" is equal to 1/16 of the avoirdupois pound. The pencil that you might be holding in your hand right now weighs about one ounce. The weight of the pencil isn't very much. If you are a grownup, a pencil will not feel like much of anything.
Many people get confused between the ounce(oz) and the fluid ounce(fl oz). Read the below article to avoid confusion and understand the difference between them. What is the difference between the dry ounce(oz) and the fluid ounce(fl oz)?
Things that weigh 1 ounce:
- a pencil
- a CD
- an AA battery
- a slice of bread
- a pen
Troy ounce
The troy ounce, abbreviated as "oz t" is equal to 1/12 of the troy pound. The troy ounce is mainly used for weighing precious metals such as gold, platinum, and silver.
Pounds (lb)
The second one is the pound. The most common type of pound used in mass measurement is the Avoirdupois Pound.
Avoirdupois Pound
The avoirdupois pound abbreviated as "lb" is equal to 16 of the avoirdupois ounces. The shoe that you have on your foot right now weighs about a pound. When comparing with the pencil, the shoe weighs a lot.
Things that weigh 1 pound:
- a soccer ball
- a large apple
- a loaf of bread
- a shoe
- a regular dinner plate
Tons
Things that weigh 1 ton:
- a baby humpback whale
- a walrus
- a black rhinoceros
- a Volkswagen Beetle
- a wild Asian water buffalo
The British Imperial and US Customary Units of Mass Measurements
| Unit and Abbreviation | Equivalents in other units of the same system | Equivalents in International System of Units (SI) |
|---|---|---|
| Avoirdupois system | ||
| 1 grain (gr.) | 1⁄7000 lb. | 64.79891 mg |
| 1 dram (dr.) | 27+11⁄32 gr. or 8.859 carats | 1.7718451953125 g |
| 1 ounce (oz.) | 16 dr. | 28.349523125 g |
| 1 pound (lb.) | 16 oz. | 453.59237 g |
| 1 US hundredweight (cwt.) | 100 lb. | 45.359237 kg |
| 1 long hundredweight | 112 lb. | 50.80234544 kg |
| 1 ton (short ton) | 20 US cwt. or 2000 lb. | 907.18474 kg |
| 1 long ton | 20 long cwt. or 2240 lb. | 1016.0469088 kg |
| Troy system | ||
| 1 grain (gr.) | 1⁄7000 lb. or 1⁄5760 lb. t. | 64.79891 mg |
| 1 pennyweight (dwt.) | 24 gr. or 7.776 carats | 1.55517384 g |
| 1 troy ounce (oz. t.) | 20 dwt. | 31.1034768 g |
| 1 troy pound (lb. t.) | 12 oz. t. or 13.17 oz. | 373.2417216 g |