Chemistry
Mole Fraction Calculator
Find the mole fraction of each component in a mixture of up to three substances.
Your inputs
Change any value to update the result instantly.
Mole fraction of A (x_A)
0.4
Mole fraction of B (x_B)
0.6
Mole fraction of C (x_C)
0
Total amount of substance
5 mol
Mole percent of A
40 %
Mole fractions are dimensionless and always add up to 1.
What this calculator does
Calculates the mole fraction of each component of a mixture of up to three substances.
What your result means
A mole fraction is the share of all the particles in the mixture contributed by one component; the fractions always sum to 1.
Formula and working
xᵢ = nᵢ ÷ Σnⱼ
- 1
Collect the inputs
Moles of component A = 2 mol; Moles of component B = 3 mol; Moles of component C (optional) = 0 mol
- 2
Apply the formula
xᵢ = nᵢ ÷ Σnⱼ
- 3
Result
Mole fraction of A (x_A) = 0.4
Frequently asked questions
Symbols and assumptions
- n_i
- Moles of component i
- x_i
- Mole fraction = n_i / sum of all n
- • Amounts are entered in moles for every component.
- • All components of the mixture are listed.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Leaving out a component makes every fraction too large. Mole fraction is not the same as mass percent.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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