Airsoft Joule Calculator Joule Calculator Calculate the kinetic energy of your RIF. FPS (Feet Per Second) BB Weight (Grams) Select weight… 0.20 g 0.25 g 0.28 g 0.30 g 0.32 g 0.36 g 0.40 g 0.43 g 0.45 g 0.48 g 0.50 g Calculate Joules