New features

Calculate with wet bulb temperature
Calculate with wet bulb temperature
Calculate other humidity parameters based on known wet bulb temperature and vice versa. If the standard psychrometer coefficients are not working for you, feel free to add your own.
Higher temperature range
Higher temperature range
Upon request, we've increased the temperature range up to +373 °C (+703 °F).
Humidity calculations and conversions made easy

The free Vaisala Humidity Calculator allows you to calculate several humidity parameters from one known value. Make unit conversions on the fly, and see the effects of changing ambient conditions, like temperature and pressure.

Calculate or convert: relative humidity, dewpoint / frostpoint, absolute humidity, water content, mixing ratio, vapor pressure, parts per million, wet bulb temperature.

The calculator speaks your language: English, Chinese, Dutch, German, Finnish, French, Japanese and Portuguese included.

A. Use online humidity calculator

System requirements
  • Macromedia Flash Player (version 7 or higher) Get Flash Player

B. Download stand-alone humidity calculator

Installation instructions
  1. Download the Vaisala Humidity Calculator
    (version 2.1, updated 2008-04-23, 1.64MB)
  2. Double-click the "Vaisala Humidity Calculator.msi" to start the installation.
  3. Follow the installer steps. Shortcuts will be created to the Start menu and Desktop.
  4. Double-click the "Vaisala Humidity Calculator" on your Desktop to start the program.
System requirements
  • Operating system: Microsoft Windows 98/2000/XP/Vista