Formula is velocity x velocity x total arrow weight(in grains) divided by 450,240.
Check out
http://www.bowsite.com/bowsite/featu...tion/index.cfm
That is where I found the formula. If you go to this site you can just punch in the numbers and you wil get your answer.
"Kill'em and Grill'em"
By The Nuge (aka Ted Nugent)