Psychrometric Calculator

W=0.62198 pwP−pwW = 0.62198\,\frac{p_{w}}{P - p_{w}}
  • T = Dry-bulb temperature (°F)
  • RH = Relative humidity (%)
  • P = Atmospheric pressure (kPa)
  • pw = Water vapor partial pressure (kPa)
  • W = Humidity ratio (kg/kg dry air)

Chart hierarchy: Saturation > Enthalpy > RH > Wet-bulb. RH is strictly clipped to saturation. Wet-bulb lines are computed via the psychrometer relation (curved Twb=const) and drawn dotted.

Temperature unit:
Enter inputs and click Calculate to plot.