Rear ride height affecting camber? Dumbass I meant Caster D’oh!!

It's called "frame angle" and it measured like any other angle, with an angle finder. No ratio needed. It's more critical when dealing with trucks that carry loads. The wrong angle can cause ill handling when loaded to maximum gross vehicle weight, usually too much caster. It's pretty easy math. Add or subtract frame angle from caster. It aint perfect but should be close. Passenger cars usually start out with zero frame angle.