Percent Composition Calculator
What mass percentage of a compound comes from this constituent? Enter the stated values to calculate this model.
Reference calculation or estimate for example inputs; assumptions and limitations apply.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Constituent mass (g) | Enter constituent mass in g; use the same basis as the other measurements. |
| Total compound mass (g) | Enter total compound mass in g; use the same basis as the other measurements. |
Understanding your result
The result is a scientific reference calculation under the model assumptions on this page. It does not assess hazards, chemical compatibility, purity, solubility, equipment limits or clinical meaning.
Common mistakes
- Using solvent volume in place of final solution volume, or mass concentration in place of molar concentration.
- Ignoring units, reaction coefficients, activity assumptions or the stated temperature/model limits.
Check your calculation
- Check the units and balance/coefficients against the worked example. For real laboratory work, verify SDS information and the applicable procedure independently.
Calculation checks, sources and review limits
What mass percentage of a compound comes from this constituent?
What mass percentage of a compound comes from this constituent? Enter the stated values to calculate this model.
Common uses
- What mass percentage of a compound comes from this constituent
How it works
Divide the constituent mass by the total sample mass on the same basis, then multiply by 100. This is mass percentage, not mole percentage.
Worked example
Enter Constituent mass: 12 g; Total compound mass: 60 g. Results: Mass percent: 20 %.