How it works
- 1Enter the requested chemistry values, formula or equation.
- 2Check units and leave a field blank only when the tool is designed to solve for an unknown.
- 3Run the calculation and review the result, formula and supporting breakdown.
← Chemistry Calculators & Laboratory Tools
BROWSER · Toolardo Chemistry Core (local JavaScript)
Molecular Weight / Molar Mass Calculator
Calculate molar mass from a chemical formula with parentheses, brackets and hydrate notation, plus element-by-element mass percentages.
✓ Runs locally in your browser✓ No account required✓ Deterministic formula-based calculation
Molar mass
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Atoms per formula unit
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| Element | Count | Atomic weight | Contribution | Mass % |
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Results are calculation aids. Verify assumptions and laboratory requirements before operational use.
Small time-saver of the dayCtrl + Y / Ctrl + Shift + ZCtrl + Y / Ctrl + Shift + Z: Redo an action after Undo
Open tip →Use Ctrl + Y / Ctrl + Shift + Z to redo an action after Undo. A small habit that keeps keyboard-heavy work moving.
About this tool
The formula parser supports standard element symbols, nested groups and hydrate dots such as CuSO4·5H2O.
Common uses
molar mass calculatormolecular weight calculatormolecular mass calculatorformula weight calculator
Frequently asked questions
Does it support parentheses and hydrates?
Yes. Examples such as Fe2(SO4)3 and CuSO4·5H2O are supported.
Is molecular weight the same as molar mass?
They are often used interchangeably in practical calculators, but molar mass is expressed in g/mol while relative molecular mass is dimensionless.
Which atomic weights are used?
The local element dataset uses standard atomic-weight values supplied by the chemistry engine.
Does this calculation run on a server?
No. The calculation runs locally in your browser with JavaScript.
Can I use the result directly in laboratory work?
Use it as a calculation aid and verify reagent form, purity, constants, assumptions and your laboratory SOP before operational use.