Relative Humidity Calculator
The Relative Humidity Calculator is a psychrometric tool used to determine the relative humidity (RH) of air when the dry bulb temperature and dew point temperature are known. Relative humidity is a measure of the amount of water vapor present in the air compared to the maximum amount of water vapor the air can hold at that specific temperature, expressed as a percentage. This calculation is fundamental in HVAC for assessing comfort conditions, predicting condensation, and managing indoor air quality. This calculator typically uses an approximation of the Magnus formula.
How Temperature Affects RH: Relative Humidity is dependent on temperature. If the actual moisture content in the air (absolute humidity or dew point) remains constant, increasing the air temperature will decrease the RH because warmer air has a greater capacity to hold moisture. Conversely, decreasing the air temperature will increase the RH, and if the temperature drops to the dew point, RH becomes 100%, and condensation may occur.
This calculation is an approximation. More precise methods might use different formulas or consider atmospheric pressure. Results are for general estimation.