you may have misplaced your decimal on that percentage. Move it one to the left. Not to mention the range of motion issues associated with the leg press, who knows what the guy is actually doing.
The decimal is fine on a 45 degree sled the force is the weight times the SIN of 45 degrees (.707 approx). As far as that translating to a squat poundage it really does not work because there are too many numerous variables between the two.
But the work done is simply the weight X SIN45 x vertical distance traveled. (the horizontal component is generally not considered in simple calculations) Also not considering coefficient of friction in the mechanism itself.
I got this info on another weight training site.
The sin 45 is what they started out with and converted it to the .707.
I know very little about training and even less math.
My question: has anyone ever squated 1414 pounds?