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Humidity Calculator

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. Humidity Calculator makes complex manual calculations and conversions a thing of the past.

The tool includes calculation and conversion for: * relative humidity, * dew point / frost point, * absolute humidity, * water content, * mixing ratio, * vapor pressure, * parts per million, * wet bulb temperature, * enthalpy, * specific volume, * density.

The new user interface works with any device, PC or mobile, and online and offline.

Eight languages are available: * English, * Chinese, * Dutch, * Finnish, * French, * German, * Japanese and * Portuguese.

Register to start the Vaisala Humidity Calculator 5.0.

  • Updated user interface – optimized also for mobile devices.
  • Works on any operating system with modern browser support - tested with IE9+, Chrome, Firefox, and Safari. Also tested with Android, iOS and Windows mobile devices.
  • No more installing software for offline use - just bookmark the calculator page or add it to the home screen on your mobile device.
Version history of the PC application

Version 3.1 2014-02-08
- Fixed a bug in the pressure unit (psig) conversion.
- New rounding function to improve calculation accuracy at extreme conditions.
- Minor user interface improvements.

Version 3.0 2013-08-27
- Entirely new calculation engine.
- New calculated parameters: enthalpy, specific volume, density.
- Replaced Basic and Advanced tabs with a customizable user interface.
End user can now decide which measurement parameters are shown on the screen.

Version 2.2 2009-11-23
- Fixed a calculation bug related to user changing both ambient conditions (T, P) at the same time. Now re-calculation happens immediately after condition has been changed.
- Fixed a bug in language negotiation that resulted in "Locale not found" errors in some localization combinations.
- New Vaisala visuals.

Version 2.1 2008-04-23
- Fixed a calculation bug related to user changing ambient conditions (T, P).
  Now all values are calculated based on new ambient conditions.

Version 2.0 2008-04-08
- Wetbulb calculation added. User can insert custom psychrometer coefficients.
- All values are calculated after changes in ambient conditions (T, P, gas type).
- Maximum ambient temperature increased to +373 °C (+703 °F).
- Portuguese localization added.

Version 1.3 2007-06-28
- Fixed a bug in pressure unit conversion when converting to or from mmHg/Torr.

Version 1.2 2007-04-05
- Improved accuracy of vapor pressure calculation in high temperatures.

Version 1.1.1 2007-02-01
- Fixed a calculation bug related to using custom gases.

Version 1.1 2007-01-15
- Comma can be used as decimal separator in addition to full stop.
- Improved calculation formula for natural gas in high pressures (above 40 bar).
- Print button introduced. Use to print the whole calculator screen.
- Copy values button introduced. Use to copy/paste calculated values to other programs, e.g. Microsoft Excel.
- Switching from Basic to Advanced mode does not reset the calculation.
- Input error messages are displayed in selected units. E.g. Temperature in Celsius or Fahrenheit.​