A door hanging tool includes a horizontal member having at least one bubble vial for the determination of the angle of a surface with respect to the horizontal member and, a vertical member having at least one bubble vial for indicating the inclination of the surface with respect to the vertical member. The horizontal member further defines anchor slots for receiving an anchor means for releasably attaching the tool to the existing pre-drilled hole for lockset from the door manufacturer, such that the user can view the bubble vial of the vertical member for indicating the vertical inclination of the door with respect to the vertical member, and can view the bubble vial of the horizontal member to determine the angle of the door with respect to the horizontal member, and can adjust the door accordingly.