Convert volume to moles for a gas at STP, room or custom conditions using PV = nRT, or for a solution from its molarity, and convert moles back to volume.

Uses PV = nZRT at the chosen conditions; Z = 1 is the ideal-gas estimate.

Absolute pressure, not gauge pressure.

Compressibility and optional mass
Default 1. Enter a known Z for the gas at the selected state; this calculator does not determine it.

Blank omits mass; enter the molar mass of the species whose moles are being calculated.

Volume To Moles Formula

For a gas at stated absolute pressure P, temperature T in kelvin and compressibility factor Z, use n = PV/(ZRT). For a solution, n = cV with concentration c in mol/L and total solution volume V in liters.

n = PV / (ZRT)

Variables:

  • n is the number of moles
  • V is the volume of the gas (liters)

For an ideal-gas estimate, use Z = 1. At 0°C and 1 atm, molar volume is approximately 22.41396955 L/mol; at 0°C and 1 bar it is approximately 22.71095464 L/mol. IUPAC standard conditions use 1 bar. The calculator states each preset explicitly and also accepts custom conditions.

Liters to Moles Conversion Table (Ideal Gas;0°C and 1 atm)
Volume (L) Moles (mol)
0.0010.000045
0.0050.000223
0.0100.000446
0.0250.001115
0.0500.002231
0.0750.003346
0.1000.004462
0.1500.006692
0.2000.008923
0.2500.011154
0.3000.013385
0.4000.017846
0.5000.022308
0.7500.033461
10.044615
1.50.066923
20.089230
2.50.111538
50.223075
100.446150
*Ideal gas at 0°C and 1 atm (101.325 kPa), Z = 1. Molar volume ≈ 22.41396955 L/mol. n = V/Vm; displayed moles rounded to 6 decimals.

What Does “Volume to Moles” Mean?

Volume alone does not determine moles. Gas calculations require pressure, temperature and a stated compressibility assumption; solution calculations require solute molarity. The calculator also reverses these relations, counts the specified chemical entities using Avogadro’s constant, and optionally calculates their mass from molar mass. It does not determine real-gas properties, phase changes or dissociation.

How to Calculate Volume To Moles?

Select gas or solution and the direction of conversion. Enter the displayed amount or volume with units, then specify gas conditions or solute concentration.

  1. First, determine the volume of the gas (V) in liters.
  2. For a gas, use n = PV/(ZRT); for a solution, use n = cV with V in liters.
  3. Finally, calculate the number of moles (n).
  4. Select Calculate. Optional molar mass adds mass; a blank molar mass omits it. Gas Z defaults to 1 and may be changed under the optional disclosure.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Volume of the gas (V) = 50 liters. At 0°C and 1 atm with Z = 1, n ≈ 2.23075167 mol.