What is the formula for moles from mass?

n = m / M, where m is mass in grams and M is molar mass in g/mol. So 18 g of water (M = 18 g/mol) is 1 mole.

What is the formula for moles from concentration and volume?

n = c × V, where c is concentration in mol/L and V is volume in L. So 100 mL of 0.5 mol/L solution is 0.05 mol.

What is the ideal gas equation?

PV = nRT, so n = PV/(RT). Use SI units: P in Pa, V in m³, T in K, R = 8.314 J/(mol·K).

What is Avogadro's number?

N_A = 6.022 × 10²³ particles per mole. The number of particles equals n × N_A.

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NSW · HSCChemistry

Mole converter

Three modes in one tool: mass + molar mass, concentration + volume, or pressure + volume + temperature for gases.

Inputs

Convert to moles fromCommon substanceMass m (g)Molar mass M (g/mol)

Result

Moles n

1.000mol

Number of particles

6.022e+23particles

n = m / M. Avogadro's constant N_A = 6.022 × 10²³ /mol.

How this calculator works

It applies whichever of the three formulas matches your inputs: n = m/M for mass-to-moles, n = c × V for solutions, n = PV/(RT) for ideal gases. The result panel also shows the corresponding number of particles using Avogadro's constant.

Common questions

What is the formula for moles from mass?: n = m / M, where m is mass in grams and M is molar mass in g/mol. So 18 g of water (M = 18 g/mol) is 1 mole.
What is the formula for moles from concentration and volume?: n = c × V, where c is concentration in mol/L and V is volume in L. So 100 mL of 0.5 mol/L solution is 0.05 mol.
What is the ideal gas equation?: PV = nRT, so n = PV/(RT). Use SI units: P in Pa, V in m³, T in K, R = 8.314 J/(mol·K).
What is Avogadro's number?: N_A = 6.022 × 10²³ particles per mole. The number of particles equals n × N_A.