Kilogram [kg]: this is the basic unit of mass in the SI system.

Gram [g]: this is one thousandth of a kilogram, often used to measure smaller masses.

Milligram [mg]: this is one thousandth of a gram, used for very small masses.

Tonne [t]: this is a unit of mass equal to 1000 kilograms, used to measure large masses.

Ounce [oz]: this is a unit of mass used in the imperial system, equal to about 28.35 grams.

Pound [lb]: this is a unit of mass used in the imperial system, equal to about 453.59 grams.

Quintal [q]: this is a unit of mass equal to 100 kilograms.

Short ton [short ton]: this is a unit of mass mainly used in the USA, equal to 2000 pounds (about 907.18 kg).

Long ton [long ton]: this is a unit of mass mainly used in the UK, equal to 2240 pounds (about 1016.05 kg).

Carat [ct]: this is a unit of mass mainly used in jewelry, equal to 0.2 grams.

Stone [st]: this is a unit of mass mainly used in the UK, equal to 14 pounds (about 6.35 kg).