Gas Density Calculator

Work out gas density instantly with clear inputs, formula shown and shareable results.

About Gas Density Calculator

Rearranging PV = nRT with n = m/M gives density directly as PM/(RT). Air at one atmosphere and 25 C works out at 1.18 kg/m3. Because molar mass sits on top, a heavier gas is denser at the same conditions - carbon dioxide at 44 g/mol is about 1.5 times air, which is why it pools in low spaces.

Formulas

Ideal gas density

rho = P x M / (R x T)

Molar volume

Vm = R x T / P

Worked example

With the default values below, Gas Density Calculator returns Gas Density of 1.1841. Change any input above and every figure here is recalculated in your browser.

Inputs used

Pressureminimum 0 Pa: 101,325 Pa
Molar mass of the gasminimum 0 g/mol: 28.97 g/mol
Temperatureminimum 0.01 K: 298.15 K

Results

Gas Density: 1.1841 kg/m3
Molar Volume: 24.465 L/mol
Specific Volume: 0.8445 m3/kg
Density Relative To Air: 1.000

Step by step

1Values used
2Ideal gas density
3Molar volume
4Gas Density= 1.1841 kg/m3
5Molar Volume= 24.465 L/mol
6Specific Volume= 0.8445 m3/kg
7Density Relative To Air= 1.000

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Does this hold at high pressure?

Less well. Near the critical point real gases deviate and a compressibility factor Z must divide the result.

Why is the molar mass entered in g/mol?

Because that is how tables list it. The calculator converts to kg/mol internally to keep the density in SI units.