nikon makes 2 models that calculates the angle. The Archers Choice and the Rifleman. Archers Choice is good for 100 yards and the Rifleman is good for around 500 yards. Archers Choice is about 250 and the Rifleman is about 10 to 20 dollars more expensive. I like the Nikon brand the best because they only show you one yardage on the screen and that is the yardage with the angle calculated. Other brands show the actual yardage, the angle, and the calculation with the angle.
Hope this helps.