Enter formula and options
Example molecular masses
| Compound | Formula | Approximate molar mass (g/mol) | Notes |
|---|---|---|---|
| Water | H2O | 18.015 | Universal solvent, basis for many solutions. |
| Glucose | C6H12O6 | 180.156 | Simple sugar, central to cellular energy. |
| Sodium chloride | NaCl | 58.44 | Common salt, important electrolyte. |
| Copper(II) sulfate pentahydrate | CuSO4·5H2O | 249.68 | Typical laboratory hydrate compound. |
| Calcium hydroxide | Ca(OH)2 | 74.093 | Strong base used in construction and chemistry. |
Values above are rounded; actual results may differ slightly due to atomic mass precision.
Formula used in this calculator
Molecular mass is calculated as the sum of each element's atomic mass multiplied by its count in the formula.
Mathematically, this can be expressed as:
M = Σ (ni × Ai)
- M is the total molecular mass in g/mol.
- ni is the number of atoms of element i.
- Ai is the standard atomic mass of element i.
The calculator uses a built-in table of approximate standard atomic masses for many common elements.
How to use this calculator
- Enter a valid chemical formula using correct upper and lower case symbols.
- Include integer subscripts for counts and use parentheses for repeated groups.
- For hydrates, use a centered dot or period, such as CuSO4·5H2O.
- Select your preferred number of decimal places for the result.
- Optionally enter an amount in moles to obtain corresponding sample mass.
- Optionally enter a sample mass in grams to find moles of substance.
- Tick the checkbox to display mass percent composition for each element.
- Click "Calculate molecular mass" to see the total and breakdown.
- Use the CSV button to export the detailed breakdown table.
- Use the PDF button to download a simple text-based report file.
For high-accuracy reporting or publication, verify values against official atomic mass data sets.
Molecular mass in your chemistry workflow
1. Linking molecular mass and mole–mass conversions
After you compute the molar mass here, you can quickly move into full stoichiometry problems. Our dedicated Mole Mass Converter Calculator connects molar mass with moles and grams for stepwise conversions and result tables.
2. Exploring detailed percent composition by element
The element breakdown table shows contributions in g/mol and optional mass percentages. For richer composition analysis across multiple compounds, you can also visit the Percent Composition Calculator , which focuses entirely on mass percent reporting.
3. Connecting molecular mass with atom counting tasks
Once a molar mass is known, you can translate between sample mass, moles, molecules, and atoms using Avogadro's number. The Advanced Atom Calculator builds on this idea and visualizes per-element atom counts in a sample.
4. Using molecular mass for gas law calculations
Gas law equations often require moles, not grams. Compute molar mass here, convert your gas sample to moles, then plug n into ideal or real-gas relations inside other chemistry tools when solving pressure, volume, or temperature problems.
5. Applying molecular mass in solution chemistry
In solution work, molar mass lets you prepare standards with precise concentration. Convert grams to moles, then use those values in concentration, dilution, or titration calculators to design experiments, verify stock solutions, and document procedures.
6. Checking formulas before balancing reactions
Balancing reactions starts with correct formulas. This calculator helps verify each compound's composition and molar mass before you move on to stoichiometric coefficients, limiting reagents, theoretical yield, and related reaction-planning tasks.
Frequently asked questions
1. What is the difference between molecular mass and molar mass?
In this tool we treat them equivalently for typical classroom problems. Molecular mass emphasizes a single molecule, while molar mass expresses grams per mole for many molecules, using the same underlying numerical value.
2. Can this calculator help with mole to mass conversions?
Yes. First compute the molar mass here. Then multiply moles by that value to get grams. For a guided workflow, you can also open our Mole Mass Converter Calculator for multi-step stoichiometry problems.
3. How accurate are the atomic masses used here?
The calculator uses standard rounded atomic weights suitable for most teaching and lab exercises. Very high precision work, such as advanced research, should reference the latest IUPAC tables or institution-approved data.
4. Does the calculator handle hydrates and nested parentheses?
Yes. You can enter formulas like CuSO4·5H2O or Ca3(PO4)2. The parser expands groups, multiplies subscripts, and adds water molecules from hydrate dots into the final molecular mass and composition.
5. Why is my result slightly different from a handbook value?
Textbooks, lab manuals, and databases may use different rounding rules or updated atomic weights. Small differences, usually in the third or fourth decimal place, are normal and rarely affect introductory calculations.
6. Can I use this for gas law or solution problems?
Definitely. Once you know the molar mass, you can convert between grams and moles, then plug n into gas law or concentration equations. Keep unit consistency when working alongside other chemistry calculators.
7. What should I do if the formula field shows an error?
Check capitalization, subscripts, and parentheses. Remove unsupported characters and verify each element exists in the periodic table. If needed, simplify the formula, compute molar mass, then use that value inside other chemistry tools.