Molecular Weight Calculator
Calculate molecular weight (molar mass) and convert between grams and moles for chemical compounds.
About This Calculator
Calculate molecular weight (molar mass) and convert mass to moles. Essential for stoichiometry, solution preparation, and chemical calculations in labs and education.
🧮 Key Formulas
Moles from Mass:
n = mass (g) / MW (g/mol)Number of Molecules:
N = n × 6.022 × 10²³📊 Common Atomic Weights
| Element | Symbol | Atomic Weight |
|---|---|---|
| Hydrogen | H | 1.008 |
| Carbon | C | 12.011 |
| Nitrogen | N | 14.007 |
| Oxygen | O | 15.999 |
| Sodium | Na | 22.990 |
| Chlorine | Cl | 35.45 |
💡 Tips
- Avogadro's number: 6.022 × 10²³ molecules/mol
- MW = molar mass: Numerically equal, different units
- For custom MW: Sum atomic weights × subscripts
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? Frequently Asked Questions
How accurate is this
This calculator uses standard formulas and provides accurate results for typical use cases. For professional or critical applications, always verify results with certified professionals or official sources.
Is this calculator free to use?
Yes, this Molecular Weight Calculator • Chemistry • Calculator is completely free to use with no registration required. You can use it as many times as needed without any limitations.
Can I use this on mobile devices?
Absolutely! This calculator is fully responsive and works perfectly on smartphones, tablets, and desktop computers.
How do I interpret the results?
The results are displayed clearly with appropriate units. Refer to the About This Calculator section for detailed information.