Molar Mass Calculator
Instantly calculate the molar mass of any chemical compound.
How to Calculate Molar Mass
1. List the Elements
Identify each unique element in the chemical formula. For H₂O, the elements are Hydrogen (H) and Oxygen (O).
2. Count the Atoms
Count the number of atoms for each element. In H₂O, there are 2 Hydrogen atoms and 1 Oxygen atom.
3. Find Atomic Masses
Use a periodic table to find the atomic mass of each element. H is ~1.008 g/mol and O is ~15.999 g/mol.
4. Multiply and Sum
Multiply each element's atomic mass by its atom count, then add all the results together for the final molar mass.
Common Compounds
A quick reference for the molar masses of some common chemical compounds.
Frequently Asked Questions
What is molar mass?
Molar mass is the mass of one mole (6.022 x 10²³ particles) of a substance, expressed in grams per mole (g/mol). It's a crucial bridge between mass and moles in chemistry.
Is molar mass the same as molecular weight?
While numerically identical, they have different units. Molecular weight is the mass of a single molecule in atomic mass units (amu). Molar mass is the mass of a mole of molecules in grams per mole (g/mol).
How does the calculator handle parentheses like Ca(OH)₂?
The calculator correctly interprets the subscript outside the parentheses as a multiplier for every element inside. For Ca(OH)₂, it counts 1 Ca, 2 O, and 2 H atoms.