Molar Mass: From Atomic Mass to Grams per Mole
A mole counts atoms, and molar mass turns that count into grams. For one element it is just atomic mass times atom count.
What is the Molar Mass Calculator?
Pick an element from the common list and enter how many atoms. The tool multiplies the element's standard atomic mass by the count. It covers single elements only, not compounds: a compound's molar mass is the sum over all its elements.
How to use it
- Pick an element.
- Enter how many atoms.
- Click Calculate Molar Mass.
Worked example
Two oxygen atoms give 2 x 15.999 = about 32 g/mol, the molar mass of O2 as an element count.
What is the molar mass of two oxygen atoms?
About 32 g/mol, from 2 times 15.999.
Frequently asked questions
Does it do compounds like water?
No. It covers one element at a time; add each element's contribution for a compound.
Are atomic masses exact?
They are standard average values; isotopes shift them slightly.