Chemistry calculator
Molecular Weight Calculator
Parse a common chemical formula into atoms and add their standard atomic weights.
Molar mass
18.015 g/mol
How the molecular weight calculator works
The parser reads case-sensitive element symbols, whole-number subscripts, and ordinary parenthesized groups. It never evaluates the input as code. Each detected element is matched against the bundled atomic-weight table.
Displayed masses use conventional standard atomic weights rounded for practical calculation. The breakdown makes formula interpretation auditable before using the result in mole conversions.
Worked example
For glucose, C6H12O6, the contributions are 6×12.011 + 12×1.008 + 6×15.999 = 72.066 + 12.096 + 95.994 = 180.156 g/mol. Water gives 18.015 g/mol, CO2 gives 44.009 g/mol, and NaCl gives 58.4398 g/mol.
Assumptions and practical limits
The parser does not support hydrate dots, leading coefficients, charges, isotope notation, square brackets, fractional subscripts, or every element. Unsupported or malformed formulas show a dash.
Atomic weights vary naturally by isotopic composition and source. Results should not be presented with more precision than the input constants justify.
Frequently asked questions
Are element symbols case-sensitive?
Yes. Co is cobalt, while CO is carbon plus oxygen.
Can it parse parentheses?
Yes, for common groups such as Ca(OH)2, including a whole-number multiplier.
Why might a valid advanced formula fail?
Hydrates, charges, isotopes, brackets, and uncommon elements are outside this deliberately safe parser.