Mass Unit Converter

To perform conversion between various mass units, start by selecting the original unit using the “From:” drop-down list and the target unit from the “To:” drop-down list. Then enter the original value into the input field on the left. The tool will instantly display the converted value at the top of the page.  

Mass units are commonly used to express the weight of objects. Hoverwer, in scientific contexts, weight is the force exerted on an object due to gravity, and mass is the measure of the amount of matter in an object.

Different units are used around the world, and the choice often depends on regional preferences and specific applications, such as trade, science, or industry.

This converter supports the following, mass, and moment of inertia units  of measure:

Atomic Mass Unit (amu): 

The atomic mass unit is a unit of mass used in chemistry to express atomic and molecular weights. One atomic mass unit is defined as one twelfth of the mass of an unbound neutral atom of carbon-12.  1 amu = 1.66053886 x 10^-27 kg.

Carat metric (ct): 

The metric carat is a unit of mass used for gemstones and pearls, with one carat equivalent to 200 milligrams:  1 ct = 0.2 g.

Gram (g): 

The gram is a metric unit of mass commonly used for small quantities.  1 g = 0.001 kg.

Hundredweight long: 

A British unit of mass equal to 112 pounds.  1 hundredweight long = 50.8 kg.

Hundredweight short: 

An American unit of mass equal to 100 pounds.  1 hundredweight short = 45.36 kg.

Kilogram (kg): 

The kilogram is the base unit of mass in the International System of Units (SI).  1 kg = 1000 g.

Microgram (µg): 

The microgram is a unit of mass equal to one millionth of a gram.  1 µg = 1 x 10^-6 g = 1 x 10^-9 kg.

Milligram (mg): 

The milligram is a metric unit of mass equal to one thousandth of a gram.  1 mg = 0.001 g = 1 x 10^-6 kg.

Ounce (oz): 

The ounce is a unit of mass commonly used in the United States and some other countries.  1 oz = 0.02834952 kg.

Ounce troy: 

A unit of mass used for precious metals, with one troy ounce equal to approximately 31.10348 grams.  1 troy ounce = 0.03110348 kg.

Pound (lb): 

The pound is a unit of mass commonly used in the United States and some other countries.  1 lb = 0.4535924 kg.

Pound troy: 

A unit of mass used for precious metals, with one troy pound equal to approximately 373.2417 grams.  1 troy pound = 0.3732417 kg.

Ton assay (AT): 

A unit of mass used in the mining industry to express the amount of valuable metal in ore. 

Ton long: 

A British unit of mass equal to 2,240 pounds.  1 ton long = 1,016.047 kg.

Metric ton (t): 

The metric ton, often simply referred to as a tonne, is a unit of mass equal to 1,000 kilograms.  1 t = 1,000 kg.

Ton short: 

An American unit of mass equal to 2,000 pounds.  1 ton short = 907.1847 kg.

Tonne: 

See Metric ton. The term "tonne" is often used internationally to refer to the metric ton.  1 tonne = 1,000 kg.