This Psychrometric Calculator allows you to compute moist air properties given only altitude, dry-bulb temperature and either wet-bulb, dew point or relative humidity. Outputs include Atmospheric pressure, Humidity Ratio, Specific Enthalpy, Specific Volume and Partial Vapor Pressure. Imperial (IP) and Metric (SI) units are supported. Toggling between unit systems is in the option menu. You can also toggle lb/lb to Grains/lb and kg/kg to Grams/kg by clicking the button with the humidity ratio units. You can remove ads through a small in-app purchase by clicking Remove Ads in the options menu. Your support will help further development on this and other HVAC related apps. Features planned for a future updates: -Mixed air calculations, process calculations, IP to SI comparison The calculations in this app are based on formulas in ASHRAE Fundamentals Handbook 2017 (Chapter 1). I am a licensed Professional Engineer in the HVAC industry with a passion for building apps that are intuitive and easy to use by fellow industry professionals. If you like this app, please consider rating it and leaving a review otherwise please send any feedback to Joe@deltaTsoftware.com or DM @DeltaTSoftware on Twitter. I plan to continue to update this app as well as add more apps to help other HVAC professionals and researchers. Thank you for your support!