[header] How to calculate molar mass [title] Understand molar mass. [step] Molar mass is the mass (in grams) of one mole of a substance. Using the atomic mass of an element and multiplying it by the conversion factor grams per mole (g/mol), you can calculate the molar mass of that element. 
[title] Find the relative atomic mass of the element. [step] An element's relative atomic mass is the average mass, in atomic units, of a sample of all its isotopes.