Calculate the mole fraction of each component in a mixture.
Mole fractions always sum to one, which makes them the natural composition variable for gas mixtures and solutions. They appear directly in Raoult’s and Dalton’s laws. Mass fractions and mole fractions differ whenever components have different molar masses, and confusing them is a common source of error.
Mole Fraction
x_A = n_A ÷ n_total, and all mole fractions sum to 1
x_A = n_A ÷ n_total, and all mole fractions sum to 1 Mole fractions always sum to one, which makes them the natural composition variable for gas mixtures and solutions. They appear directly in Raoult’s and Dalton’s laws.
Mass fractions and mole fractions differ whenever components have different molar masses, and confusing them is a common source of error.
This calculator takes 3 inputs: Moles of component A, Moles of component B, Moles of component C. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.