BB FPS Converter is a app that helps you convert between velocity, weight, and energy of an airsoft BB, paintball, or airgun bullet. The values changes as you enter the data. It remembers your value, so that you don't have to keep re-entering your common settings.
It will work for any firearm that uses air to propell its ammunition. It does not matter whether the ammunition is made out of plastic, metal, or paint. It works for automatic electric gun (AEG), gas blowback, spring pistols and rifles, and paintball markers alike.
The velocity (speed) is specified in feet per second (FPS). The weight is specified in gram (g). The energy is specified in joules (j).