Enter the molar mass and molar volume into the calculator to determine density. For gases, the molar volume depends on temperature and pressure (use the Ideal Gas tab if you know P and T). Results are shown in the unit you select (default: g/L).

G/Mol to Density Calculator

Gas
Liquid / Solid

Enter a molar mass (or pick a gas) to get density at the chosen conditions.


Related Calculators

g/mol to Density Formula

The following formula is used to calculate density from molar mass and molar volume (where Vm is the actual molar volume at the stated conditions/phase). For an ideal gas, Vm = RT/P, so ρ = M·P/(R·T).

D = \frac{M}{V_m}

Variables:

  • D is the density (g/L)
  • M is the molar mass (g/mol)
  • V_m is the molar volume (L/mol)

To calculate the density, divide the molar mass (M) by the molar volume (V_m).

Molar Mass to Gas Density Conversion Table (ρ = M / Vm, Vm = 22.414 L/mol at 0°C, 1 atm)
Molar Mass (g/mol) Density (g/L)
2.015880.090
4.0026020.179
16.04250.716
17.03050.760
20.17970.901
28.01011.250
28.01341.251
28.05321.252
28.971.293
30.00611.339
30.071.342
31.99881.428
39.9481.783
44.00951.965
44.0971.968
46.00552.054
48.0002.143
58.1242.595
64.0662.860
146.066.520
Assumes ideal-gas molar volume Vm = 22.414 L/mol (0°C, 1 atm). Relation: ρ (g/L) = M (g/mol) ÷ Vm (L/mol).

What is Density?

Density is a measure of mass per unit volume. It is an important property of a substance and can be used to help identify materials, estimate buoyancy, and support process and equipment design. In chemistry, density is commonly used to convert between mass-per-volume quantities (such as g/L) and molar quantities (such as mol/L) when the molar mass is known.

How to Calculate Density from g/mol?

The following steps outline how to calculate density from molar mass and molar volume.


  1. First, determine the molar mass (M) in grams per mole (g/mol).
  2. Next, determine the molar volume (V_m) in liters per mole (L/mol) for the substance at the conditions of interest (for an ideal gas, V_m = RT/P).
  3. Use the formula from above: D = M / V_m.
  4. Finally, calculate the density (D) in grams per liter (g/L).
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem :

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

Molar Mass (M) = 44.0095 g/mol (Carbon Dioxide, CO2)

Molar Volume (V_m) = 22.414 L/mol (Ideal Gas at STP: 0°C, 1 atm)

Density (D) = 44.0095 ÷ 22.414 = 1.964 g/L