⚗️ Molecular Weight Calculator
Enter chemical formula to get molecular weight in g/mol. Free molar mass calculator.
Molecular Weight
18.015 g/mol
Common compounds
FAQs
Q: How is molecular weight calculated?
A: Multiply the atomic weight of each element by the number of its atoms, then add the totals. For H2O: 2 x 1.008 + 15.999 = 18.015 g/mol.
Q: What is the difference between molar mass and molecular weight?
A: They are very similar in practice. Molar mass is expressed as grams per mole of substance, while molecular weight usually refers to relative mass without units.
Q: Why are capital letters important in a formula?
A: Element symbols are case-sensitive. Cl means chlorine, while cl is incorrect. H is hydrogen, and H2 means two hydrogen atoms.