Mass And Weight Converter

Mass And Weight Converter is online conversion calculator that allows you to convert units of weight/mass between various measurement systems. You can easily convert kilograms to pounds, pounds to ounces, metric tonnes to pounds, long tons to short tons, pounds to kilograms etc. You can easily check carat weight in grams or grains. It supports atomic masses also (such as 'Atomic Mass Unit', MeV/c2,Planck Mass). Our examples show you how to calculate kilograms vs pounds (pounds vs kilograms) and give you fast access to some interesting weights and masses (e.g. the biggest diamond carat weight).

Accuracy number of significant decimal digits
Metric System
milligram [mg] gram [g] decagram [dag] kilogram [kg] metric tonne [T]
Atomic Mass Unit [u],[amu] or [Da] MeV/c2 Planck Mass
Imperial & US System
ounce [oz] pound [lb] stone US hundredweight [cwt] Imperial hundredweight [cwt] short ton [S/T] long ton [L/T] grain [gr]
carat [ct] quintal [q]
Mass of the Electron
Electron Mass is equal 9.11*10-31kg (0.0005u, 0.511 MeV/c2) and it is approximately 1/1836 of proton mass.
Mass of the Proton
Proton Mass is equal 1.6726*10-27kg (1.0073u, 938.272 MeV/c2) an it is approximately equal to neutron mass and approximately 1836 times greater then the mass of an electron.
Mass of the Neutron
Neutron Mass is approximately equal to proton mass and is equal 1,6748*10-27 (939,55 MeV/c2, 1.0087u).
Carbon C12 Mass
Carbon isotop C12 contains 6 neutrons and 6 protons. Its mass is used as a base to define an Atomic Mass Unit and its 12u by definition. (Earlier Atomic Mass Unit was defined as 1/16 of O16)
Mass of the Moon
Lunar Mass is widely used in astronomy to describe masses of other moons. Lunar Mass is approximately equal 7.3477 × 1022 kg or 1.62 × 1023 pounds
Mass of the Earth
Earth Mass is widely used in astronomy to describe masses of other planets. Earth Mass is approximately equal 5.9736 × 1024 kg or 1.32 × 1025 pounds
Mass of the planet Jupiter
Jupiter Mass is widely used in astronomy to describe masses of other planets, gas giants and extrasolar planets. Jupiter Mass is approximately equal 1.8986 × 1027 kg or 4.1857 × 1027 pounds The Jupiter was choosen as a base because it is the largest planet in our solar system.
Mass of the Sun
Solar Mass is widely used in astronomy to describe masses of other stars and galaxies. Solar Mass is approximately equal 1.9889 × 1030 kg or 4.3848 × 1030 pounds
Cullinan Diamond Mass
The Cullinan Diamond is the largest diamond ever found. Its mass was 3106.75 ca (carats) (621.35 grams, 1.3698 pounds). The famous Koh-i-noor diamond weights 'only' 105 ca (21 grams, 0.0463 pounds) The stone was found in Cullinan, Gauteng, South Africa, on January 25, 1905 by Frederick Wells. It was divided into 9 large and 96 smaller stones by Joseph Asscher. The largest part named 'Great Star of Africa' or Cullinan I weights 530.2 ca.
Kilogram vs. Pound Example
If your weight or mass is given in kilograms and you want to know pound weight/mass, you should type quantity of kilograms in the edit box labeled 'kilogram'. You will get pound weight in the edit box labeled 'pound [lb]'. On the other hand, if you want to know kilogram weight (or tonne, long ton, stone, carat weight) of any substance/item knowing how many pounds it weights, simply type the pound weight into the edit box labeled 'pound [lb]' and the system will give you an answer.
Fundamental unit of mass in the International System Of Units (SI) is kilogram [kg]
UnitIn kilograms
Metric System
milligram [mg]0.000001
gram [g]0.001
decagram [dkg]0.01
kilogram [kg]1
metric ton1000
Us & Imperial System
ounce [oz]0.028349523
pound [lb]0.45359237
US hundredweight [cwt]45.359237
Imperial hundredweight [cwt]50.80234544
short Ton [S/T]907.18474
long Ton [L/T]1016.0469088
grain [gr]0.00006479891
carat [ct]0.0002
quintal [q]100