Psychrometric Calculator
Calculate key psychrometric properties of air including relative humidity, dew point, humidity ratio, and enthalpy based on dry bulb temperature and wet bulb temperature.
Published by:
isCalculator Editorial Team
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How to Use the Psychrometric Calculator
This calculator computes key air properties from dry bulb temperature, wet bulb temperature, and atmospheric pressure. All values must be in metric units (°C and kPa).
- Enter Dry Bulb Temperature (°C) – the ambient air temperature.
- Enter Wet Bulb Temperature (°C) – must be ≤ dry bulb temperature.
- Adjust Atmospheric Pressure (kPa) – default is 101.325 kPa (standard). Change only if needed.
- Click “Calculate” – results appear below.
Outputs explained:
- Relative Humidity (%) – ratio of actual vapor pressure to saturation vapor pressure.
- Dew Point (°C) – temperature at which condensation begins.
- Humidity Ratio (kg/kg) – mass of water vapor per kg of dry air.
- Enthalpy (kJ/kg) – total heat content of moist air.
Tip: Ensure wet bulb is not higher than dry bulb, or the calculator will show an error.
Previous Results
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Frequently Asked Questions
Psychrometry is the study of the thermodynamic properties of moist air, including temperature, humidity, and energy content.
Relative humidity is the ratio of actual vapor pressure to saturation vapor pressure at the dry bulb temperature, expressed as a percentage.
Wet bulb temperature is the temperature a parcel of air would have if cooled to saturation by evaporation of water into it, measured with a wet-bulb thermometer.