Enter a chemical formula like C6H12O6 or Ca(OH)2 to get its molar mass and per-element breakdown.
Understanding the molecular weight calculation
This calculator parses a chemical formula โ including parentheses and multipliers โ and sums the atomic weights to give the molar mass in grams per mole.
It covers the common elements used in most chemistry problems.
The default scenario, worked through
As an example, with a chemical formula of H2O, the calculator returns a molar mass of 18.015. Alongside it, Atoms comes out at 3. Change any field and every figure updates as you type.
Step by step
- Type a chemical formula.
- Use parentheses for groups, e.g. Ca(OH)2.
- Read the molar mass and element breakdown.
The maths behind it
molar mass = ฮฃ (atomic weight ร count) for each element
Frequently asked questions
How do I write a formula?
Use element symbols with counts, like H2O or C6H12O6, and parentheses for repeated groups, like Ca(OH)2.
What is molar mass?
The mass of one mole of a substance in grams, found by adding the atomic weights of all its atoms.
Which elements are supported?
The common elements found in most chemistry problems. Unusual symbols are flagged as unknown.