Disclosed is a guidance system that helps an earthmoving machine operator to control exactly to what elevation to dig. The system includes an electronic sensing device and a display monitor. In one embodiment, the electronic sensing device includes a distance measuring sensor (LDM), an elevation detecting sensor, an orientation sensor, and a steering mechanism for the LDM. The sensing device is mounted to an earthmoving machine, and sends signals to the display showing the machine operator where to move the digging tool for digging to the desired elevation. The various sensors in the sensing device are calibrated at the factory, so the sensing device can be mounted to an earthmoving machine and then be immediately used by that machine without needing any calibration that involves the machine itself, which is a huge advantage for the equipment operator. The measurements are made via non-contact sensors, thereby preserving the jobsite surface.