This looks to be a handy tool. You enter the body diameter, the rocket weight, drag coefficient, and the motor type and you get an estimation of how high it will go and even how long it will take to land if you add the parachute size. You can use it for other things too, like seeing if you could launch a full roll of paper towels into the air. You can, it takes about 3 D-12 motors. 🙂