Air Density Calculator

Air density is the mass of air per cubic meter. It increases with rising atmospheric pressure, falling temperature and falling humidity. The latter is because a H2O molecule weighs less than a N2 or O2 molecule. The saturation vapor pressure can be calculated separately. If this is not specified, the calculation is based on the formula for air over water. Please enter at least air pressure and temperature.

Atmospheric pressure hPa (= mbar):
Temperature in °C:
Relative humidity in %:
Saturation vapor pressure in hPa:

Gas constant of moist air:
Air density in kg/m³:

The calculation is:

Gas constant of moist air: Rf = Rt / [ 1 − φ * E/p * ( 1 − Rt/Rd ) ]
With humidity φ between 0 and 1, saturation vapor pressure E in pascals, atmospheric pressure p in pascals, as
the gas constant of dry air Rt = 287.058
and the gas constant of steam Rd = 461.523
The unit of the gas constant is J/(kg*k) = Joule / ( Kilogramm * Kelvin)

Air density = p / ( Rf * T)
T is the temperature in kelvins = temperature in °C + 273.15

Physics commonly uses SI units. Here is a calculator to convert lengths, temperature, pressure, speed and other units.

Barometer and air calculators © Webprojects | Online Calculators | German: Barometer-Rechner | Contact & Privacy