⚗️ Molecular Weight Calculator
Molar mass is the weight of one mole of a substance — the number you need to convert grams to moles in any chemistry problem. Type a formula such as H2O, CO2 or NaCl and the calculator sums the atomic weights.
Currently supported elements are H, C, N, O, Na, Cl and S, which cover the most common classroom and lab formulas.
How to use this calculator
Type a chemical formula such as H2O or NaCl. The calculator parses it and returns the molar mass in g/mol with an element-by-element breakdown.
- Type the Chemical formula, for example H2O.
- Read the molecular weight in g/mol instantly.
- Check the breakdown line to see each element's contribution.
- Stick to H, C, N, O, Na, Cl and S for supported elements.
Frequently asked questions
What does the Molecular Weight Calculator compute?
It adds up the atomic weights of every atom in a chemical formula to give the molar mass in grams per mole, plus a breakdown like H x 2, O x 1.
Which elements are supported?
H, C, N, O, Na, Cl and S, which cover the most common classroom and lab formulas. Anything else triggers a message naming the unsupported element.
Can you give a worked example?
H2O is 2 times 1.008 plus 15.999, giving 18.015 g/mol. NaCl is 22.99 plus 35.45, giving 58.44 g/mol.
How should I type the formula?
Use standard notation with element symbols capitalized correctly and counts as plain digits: H2SO4, CO2, NaCl. Spaces are ignored, but parentheses for groups like (NH4)2SO4 are not supported.