A method for calibrating a radar sensor of a vehicle includes fixing the vehicle in place on a transport; moving the vehicle along a route past a reflector for radar waves using the transport; irradiating the reflector with radar waves and receiving reflected radar waves using the radar sensor while the vehicle is moved along the route; determining a position and/or an alignment of the radar sensor relative to the reflector multiple times based on the reflected radar waves; and spatially calibrating the radar sensor based on the ascertained positions and alignments relative to the reflector by ascertaining a position and/or an alignment of the radar sensor relative to the vehicle.