Molar mass converter
Convert molar mass between g/mol, kg/mol and daltons: the weight of one mole of a substance.
That's about the same as water. One mole of it weighs about 18.02 g.
What it means
How heavy is that molecule?
Values are standard atomic weights. Isotopes of the same element differ, which is how mass spectrometry tells them apart.
Every unit
Your molar mass in every unit
Learn
Three things worth knowing
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Add up the atoms
Water is 2 hydrogens (1.008 each) plus one oxygen (15.999): 18.015 g/mol. Any formula works the same way.
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Carbon-12 as the ruler
For decades the dalton was defined as one twelfth of a carbon-12 atom. Since 2019 it is tied to the fixed value of Avogadro’s constant instead.
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Atomic weight is not mass number
Chlorine’s atomic weight is 35.45 because nature mixes two isotopes. No single chlorine atom weighs that; it is an average.
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Background
About molar mass
Molar mass is the mass of one mole, in grams per mole. It is numerically the same as the molecular mass in daltons, which is the whole convenience of the mole.