Also don't forget to shoot for the horizontal distance to the target.....in other words shoot the distance as measured from the base of your tree to the animal not from your stand height to the target.(assuming that is a straight and level line)
This is even more of factor if your stand is set on a sidehill and the animal is on the downhill side. Only now you have to figure the distance from the base of your tree to a point ABOVE the target on a straight level line. In this case you would try to figure the distance from the base of your tree to a point at that same level next to the target. Does that make sense?