# Density of an Ideal Gas

Written by Jerry Ratzlaff on . Posted in Thermodynamics

Density of an ideal gas (volumetric mass density) is greatly affected by pressure.

## Density of an Ideal Gas formula

 $$\large{ \rho = \frac {M \; p_{atm} }{R \; T_a} }$$

### Where:

 Units English Metric $$\large{ \rho }$$   (Greek symbol rho) = density of an ideal gas $$\large{\frac{lbm}{ft^3}}$$ $$\large{\frac{kg}{m^3}}$$ $$\large{ T_a }$$ = absolute temperature $$\large{R}$$ $$\large{K}$$ $$\large{ p_{atm} }$$ = atmospheric pressure $$\large{\frac{lbf}{in^2}}$$ $$\large{Pa}$$ $$\large{ M }$$ = molar gas $$\large{ft^3}$$ $$\large{m^3}$$ $$\large{ R }$$ = molar gas constant $$\large{\frac{lbf-ft}{lbmol-R}}$$ $$\large{\frac{J}{kmol-K}}$$