The pilot said that during a landing approach to runway 33 at Cowra the engine suffered a complete loss of power. The aircraft was landed in a paddock near the aerodrome. During the landing roll the aircraft struck a fence, resulting in a steel stake penetrating the left side of the fuselage and the adjacent rear passenger seat. From information supplied by the pilot, the loss of power was probably due to fuel exhaustion as a result of his miscalculation of the overall fuel consumption rate of the aircraft. This occurrence was not the subject of an on-site investigation. The report is based on information supplied by the pilot.