Mole Fraction Calculator
Find the mole fraction of every component in a mixture and see how the composition divides into a whole.
Total moles: 10 mol
Components
3Nitrogen
20%
Oxygen
30%
Argon
50%
- 1
Total moles
2 + 3 + 5 = 10 - 2
Mole fraction of first component
2 ÷ 10 = 0.2000
How does this calculator work?
Mole fraction is each component’s moles divided by the total moles in the mixture: xᵢ = nᵢ / Σn. Enter the moles of every component, and the calculator returns each dimensionless fraction. All fractions sum to 1 (100%), and the result is independent of temperature and pressure.
Formula
How this is calculated
Enter the number of moles of each component as a comma or newline separated list. If you only have masses, divide each mass by its molar mass first to obtain moles, then enter those values. Optionally enter component names in the same order to label the results.
The calculator sums every entry to obtain the total moles in the mixture (Σn), then divides each component's moles by that total to give its mole fraction xᵢ = nᵢ / Σn. Mole fractions are dimensionless and, by construction, always add up to exactly 1 (or 100% when expressed as a percentage). The donut chart shows each fraction as a slice of the whole.
All entries must be non-negative, and the total must be greater than zero, otherwise the fraction is undefined. Negative or non-numeric values are rejected. Because mole fraction depends only on amount of substance, it is independent of temperature and pressure, unlike concentrations expressed per unit volume.
Frequently asked questions
Convert each mass to moles by dividing by the substance’s molar mass (n = m / M), then enter the resulting moles. Mole fraction is defined in terms of amount of substance, not mass.
Each fraction is a part of the total moles, so summing nᵢ / Σn over every component gives Σn / Σn = 1. Expressed as percentages they sum to 100%.
No. Mole fraction is a ratio of amounts of substance, so it is unaffected by temperature or pressure, making it useful for gas mixtures and solutions alike.
Also known as
TG we-Calculate Editorial Team. (2026). Mole Fraction Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mole-fraction-calculator
TG we-Calculate Editorial Team. "Mole Fraction Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/mole-fraction-calculator.
TG we-Calculate Editorial Team, "Mole Fraction Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mole-fraction-calculator
@misc{wecalculate_mole_fraction_calculator, title = {Mole Fraction Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mole-fraction-calculator}}, year = {2026}, note = {TG we-Calculate} }
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