The properties of air vary from place to place, by time of year, and even hour by hour.  For many practical reasons, from human comfort to industrial process design, the ability to forecast and control the properties of air is important. 

These on-line psychrometric calculators make air property determination simple.  Enter three input variables of your choosing, and a consistent set of values for your choice of other properties of will be calculated.   

• See list of available input and output properties below the English and Metric calculators

• Select your desired set of properties using the drop-down choices

• Specify two input properties (e.g. dry bulb temperature and % relative humidity)

• Specify the site elevation (or the local ambient pressure)  

• Click "Calculate" to obtain other physical and thermodynamic property values