Carbon Footprint Calculator is a freeware application programmed to help in calculating your carbon footprint. The total CO2 number is based on your specific lifestyle habits and daily activities which you enter into the program. One area you fill out is energy use including fuel oil, natural gas, and electric usage. You also fill in the state so we can figure on how that state generates its power. Anther area is transportation such as car, bus, train, and airplane. You can enter in a number of vehicles and the mile per gallon for each, if needed. Next you enter your recycling habits, where you get your food, recreational activities, and more. All of this data is used to give an estimate on your carbon footprint. Once you have filled out the main screen the software gives you your total carbon dioxide output for one year. You can compare this to the rest of the world and the United States. You can also look at the detailed data to find ways and areas where you can best reduce your emissions and make an impact in lowering your overall carbon footprint. Other features include multiple cars, files, details, English and metric units, and help. The software is free with no time limits or feature restrictions.