Definitions of units for mass

dram

The unit of weight in avoirdupois system (symbol dr), which weighs 1⁄256 pound or 1⁄16 ounce.

grain

The unit of weight in avoirdupois system, which weighs 1⁄7000 pound. It is about 64.79891 milligram.

hundredweight [UK]

Avoirdupois unit of weight used in Britain (symbol cwt). It is also called long hundredweight to distinguish it from short hundredweight. 1 long hundredweight is equal to 4 quarter (long) or 112 pound

hundredweight [US]

Avoirdupois unit of weight used in America (symbol cwt). It is also called short hundredweight to distinguish it from long hundredweight. 1 short hundredweight is equal to 4 quarter (short) or 100 pound.

kilogram

The SI unit of the mass (symbol kg). It is equal to the international prototype of the kilogram. The name is formed by attaching the SI prefix "kilo" to the word "gram" (CIPM 1967).

ounce

Unit of weight in Avoirdupois system (symbol oz). 1 ounce equals 1/16 pound or 28.35 gram.

pound

Unit of weight in Avoirdupois system (symbol lb). 1 pound equals 16 ounce or 0.45359237 kilogram.

quarter [UK]

Avoirdupois unit of weight used in Britain (symbol cwt). It is sometimes called long quarter to distinguish it from the quarter used in US. 1 long quarter is equal to 2 stone or 28 pound.

quarter [US]

A traditional Avoirdupois unit of weight equal to 1/4 short hundredweight used in the United States. One quarter equals 25 pounds (11.3398 kilograms).

quarter [US, ton]

Unit of weight informally used in the U.S., which means 1/4 ton, or 500 pound.

stone

Avoirdupois unit of weight (symbol st). 1 stone equals to 14 pound.

ton [UK]

Avoirdupois unit of weight used in Britain. It is also called long ton to distinguish it from short ton. 1 long tom is equal to 20 hundredweight (long) or 2240 pound.  

ton [metric]

Unit of mass in metric system, also called tonne (symbol t). 1 metric ton is equal to 1000 kilogram.

ton [US]

Avoirdupois unit of weight used in America. It is also called short ton to distinguish it from long ton. 1 short tom is 20 hundredweight (short) or 2000 pound.

tonne

Unit of mass in metric system, also called metric ton (symbol t). It is equal to 1000 kilogram.