Abstract: A rangefinder for scopes and binoculars in which a transparent display has a scale or other height-determining member to determine the height of the object viewed through the display and compare with a known object height selectively displayed on the same display, the actual height and known height being recorded and processed through a programmable logic circuit which calculates the range or distance of the object from the display based on actual height and known height. The programmable control circuit may also include a list of known object heights which can be selected and displayed on the display.