Calculate each component mole fraction
Mole fraction describes one component amount divided by the total amount of all listed components. Enter two to twelve rows using component name and moles, or choose mass mode and provide name, mass in grams, and molar mass in g/mol. Mass mode first converts each component to moles. The calculator then totals those amounts and displays each fraction, keeping the normalized mole basis visible rather than mixing masses and moles in one denominator.
Use xi equals ni divided by total moles
For component i, xi = ni/Σn. All fractions are dimensionless, non-negative, and should sum to one apart from display rounding. Two moles of water mixed with one mole of ethanol give fractions 2/3 and 1/3. Multiplying every component amount by the same positive factor leaves the fractions unchanged. A repeated component name is rejected so the same material is not presented twice as though it were two independent fractions.
Convert component masses before normalizing
Masses cannot be divided directly to obtain mole fraction because substances have different molar masses. In mass mode, each amount is ni = mi/Mi. For example, 36.03 g of water is about 2 mol, while 46.07 g of ethanol is about 1 mol. Only after those conversions are the amounts added. Use the molar mass of the actual chemical form and a common mass unit for every row; purity or hydration corrections must be handled before entry.
Check the component set and fraction sum
Add the displayed component moles to reproduce the total, then divide one row independently to reproduce its fraction. Add all displayed fractions and expect a value near one. The answer depends on the component set: omitting solvent, dissolved gas, or another material changes every fraction. Mole fraction is not mass fraction, volume fraction, molarity, molality, partial pressure, or thermodynamic activity, although those quantities may be related under additional assumptions.
Mixture assumptions and private calculation
The calculation treats the entered components as a bookkeeping list and does not model reaction, association, dissociation, evaporation, non-ideal mixing, or phase separation. A fraction alone does not establish safety, equilibrium, vapour pressure, or physical compatibility. Use composition and property data appropriate to the real system when those effects matter. The page does not store component names or amounts after the current tab is closed.
The values are calculated in the current browser tab. NexaCurrent does not upload the quantities, formulas, chemical names, element choices, or other information entered here, and no account is needed. Copying is a deliberate action after the answer and working are visible. Refreshing or leaving the page clears the current calculation, so keep a copied result if it is needed for later study.