BTU Calc is a quick and simple reference for anyone who would like to know how much Natural Gas, or Propane, their gas driven appliances will consume. If given the orifice size and/or drill bit wire size, pressure and orifice coefficient, the app will output estimated BTU usage. It also has the ability to forecast the price per hour of gas consumption given a particular dollar amount per 1000 cubic ft of Natural Gas or gallon of Propane. This app is not meant for precise laboratory measurements. Many variables (i.e. temperature, pressure drop, etc.) are being held at nominal levels. With that said, it is a great tool for most low pressure situations where a quick estimate is required.