Calculator of Air

Calculate as if directly using a psychrometric chart. Computes only physically valid states with Wexler–Hyland equations, numerical methods, and robust error handling.

This is a psychrometric (moist air) calculation app used in over 20 countries worldwide. It allows you to quickly and easily calculate humidity-related properties with a calculator-like interface. The app adopts the Wexler–Hyland formulation combined with numerical analysis, providing highly accurate and stable results even under extreme atmospheric conditions.

Supported parameters The following six parameters are supported:

• Dry-bulb temperature
• Wet-bulb temperature
• Dew point temperature
• Relative humidity
• Humidity ratio
• Enthalpy

By entering any two of these parameters, all remaining values are calculated automatically. For example, you can determine the dry-bulb temperature when the dew point and relative humidity are known. Ideal for HVAC design, cleanroom management, and industrial drying processes where precision is non-negotiable. When used together with the companion app “HumidCalc”, additional air-property parameters can be viewed (please refer to the companion app description for details).

■ Input range and safety checks

• Temperature: -273.15 °C to 99.97 °C (-459.67 °F to 211.95 °F)
• Relative Humidity: 0 %RH to 100 %RH
• Atmospheric pressure is fixed at the standard atmospheric pressure (1013.25 hPa / 29.92 inHg). If physically invalid values are entered(e.g., wet-bulb temperature higher than dry-bulb temperature), an error message is displayed before calculation is executed.

■ Additional features

• Supports both Celsius (°C) and Fahrenheit (°F)
• Toggleable click sound
• Available in Japanese, English, and Traditional Chinese

■ Memory function After performing a calculation, tapping one of the following buttons(Dry-bulb, Wet-bulb, Dew point, Relative humidity, Absolute humidity, or Enthalpy) stores that value for subsequent calculations. By using this function, continuous air-state calculations are possible. For example, when outdoor temperature and humidity and indoor temperature are known(assuming no latent heat load), you can first calculate and store the outdoor dew point, then input the indoor temperature to easily obtain the indoor humidity.

■ Disclaimer

1. Recommended operating temperature range is approximately 0 °C to 40 °C. Extremely unusual conditions may result in inaccurate calculations.
2. Minor numerical errors may occur due to floating-point arithmetic.
3. The developer assumes no responsibility for any damages resulting from the use of this app.