Air Density Calculator
Find the density of humid air given its temperature, pressure, and relative humidity — useful for aerodynamics, ballistics, and HVAC estimates.
What this calculates
Air density changes with temperature, pressure, and how much water vapor is present. This calculator estimates the density of humid air, which matters for aircraft performance, projectile ballistics, HVAC sizing, and sports science (like how far a ball travels).
The formula
Moist air density is found by treating dry air and water vapor as separate ideal gases: ρ = (Pdry / (Rd·T)) + (Pvapor / (Rv·T)), where Rd = 287.05 J/(kg·K) for dry air and Rv = 461.495 J/(kg·K) for water vapor, T is absolute temperature in kelvin, and the vapor pressure is derived from relative humidity and saturation vapor pressure.
Results are estimates for general engineering and educational reference.