How to calculate molar mass

 Molar masses of chemical compounds are equal to the sums of the molar masses of all the atoms in one molecule of that compound. After that, If you have a subscript in a chemical formula, then you multiply the number of atoms of anything next to that subscript by the number of the subscript. I'm kinda new to this stuff. Hopefully I helped :/

Molar mass is the sum of all atomic masses in a given compound in relative grams. To explain how to calculate the Molar mass, let me show you an example.

Calculate the Molar mass of H2O

now, atomic mass of H - 1
Atomic mass of O - 16

Now, molar mass = 1(2) + 16

= 2 +16
= 18 u = 18 grams (relative mass in grams)