Estimate air density using temperature, pressure, and relative humidity. This calculator shows air density in kg/m³, lb/ft³, and g/m³, plus dry air pressure, water vapor pressure, and density comparison notes.
Air temperature:
Enter the air temperature. The calculator converts Fahrenheit, Celsius, or Kelvin to Kelvin for the formula.
Air pressure:
Enter the air pressure. Standard sea level pressure is commonly listed as 1013.25 hPa.
Relative humidity:
Enter the humidity percentage. The calculator estimates water vapor pressure and dry air pressure.
Air density result:
The result estimates the mass of air per unit volume under the entered conditions.
An air density calculator is useful for weather, HVAC, aviation, engines, sports performance, airflow, pressure checks, altitude comparisons, and general atmosphere calculations.
Air density changes with temperature, pressure, and humidity, so the same location can have different density values under different weather conditions.
Your result shows the estimated air density for the conditions entered. Higher air density means more air mass in the same volume. Lower air density can happen when air is warmer, pressure is lower, altitude is higher, or humidity is higher.
Air density is the mass of air in a given volume, commonly measured in kilograms per cubic meter, or kg/m³.
A common standard sea level air density reference is about 1.225 kg/m³ at 15°C and 1013.25 hPa.
Humidity slightly decreases air density because water vapor is less dense than dry air.
When air warms, the molecules spread out more. At the same pressure, warmer air has less mass in the same volume.