Molar Mass Calculator (Molecular Weight)
Type any chemical formula (e.g. H2O, Ca(OH)2, C6H12O6) to compute its molar mass.
Case-sensitive: Co = cobalt, CO = carbon monoxide.
Result
Molar Mass
74.092 g/mol
Atoms
Ca O2 H2
Element count
3
Total atoms
5
Concept
Molar mass is the mass of one mole (6.022 × 10²³ particles) of a substance, in g/mol. It equals the sum of the atomic masses of all atoms in one formula unit.
For a compound like H₂O: 2 × 1.008 (H) + 1 × 15.999 (O) = 18.015 g/mol. For ionic compounds and polymeric structures, the formula unit is used rather than a single molecule.
Molar mass is the bridge between the macroscopic world (grams you can weigh) and the microscopic world (moles of atoms/molecules). It makes stoichiometry calculations possible.
Formula
M (g/mol)=Σ ( Atomic Masselement × Subscript count )
Variables
Mg/mol- Molar mass of the compound.
Atomic Massg/mol- The standard atomic weight of each element from the periodic table.
Subscript count- The number of times that element appears in one formula unit — includes nested parentheses like Ca₃(PO₄)₂.