Mole Fraction Calculator
Determine the mole fraction of each component in a mixture and normalise compositions with ease.
Mixture components
Optional when entering moles directly.
Optional when entering moles directly.
Results
Total moles in mixture: 3
| Component | Moles | Mole fraction |
|---|---|---|
| Component A | 1 | 0.333333 |
| Component B | 2 | 0.666667 |
How to Use This Calculator
List mixture components
Add each chemical species to the table and give it a clear name.
Select input type
Use moles if you already know them, or choose mass to convert using molar mass.
Enter amounts
Fill in moles or masses for each component. Provide molar masses when using mass input.
Review mole fractions
The results table lists moles and mole fractions that sum to 1.
Formula
xi = ni / sum(nj)
Mole fraction equals the moles of a component divided by the total moles of all components in the mixture.
Example
For a solution with 0.50 mol NaCl and 9.50 mol H2O: xNaCl = 0.50 / (0.50 + 9.50) = 0.05 and xH2O = 0.95.
Full Description
Mole fraction expresses composition without units, making it ideal for gas mixtures, solutions, and solids. It remains constant with temperature, so it is widely used in thermodynamic calculations.
This calculator accepts direct mole inputs or converts masses to moles using molar masses. The resulting fractions always sum to 1, providing a normalised composition for Raoult's law, vapor-liquid equilibrium, or reporting mixture data.
Frequently Asked Questions
Do mole fractions always sum to 1?
Yes. Dividing each component's moles by the total ensures the fractions add up to unity.
Can I mix different physical states?
As long as you can compute moles for each component, mole fractions apply regardless of state.
How accurate are mass conversions?
Accuracy depends on molar mass values and mass measurements. Use precise data for the best results.
Does this give mole percent?
Mole percent is mole fraction multiplied by 100. Multiply the output if you need percent format.
Can I export the results?
Copy the table into a spreadsheet or lab notebook. Export features may be added later.