A method for estimating real machine settings in hypoid gear cutting is proposed. The coordinates of many points on the gear tooth surface are measured using a coordinate measuring machine, and a geometrical gear tooth surface which is strictly defined from the machine settings on a Gleason hypoid generator is estimated by the method of least squares so that the surface can fit the data of coordinate measurements. The real machine settings can be determined conversely from the estimated tooth surface. The measured hypoid gears are in practical use and the tooth bearing of the gears is acceptable. The path of contact is calculated using the estimated results and compared with the actual tooth bearing. The validity of the proposed method is confirmed by this comparison. The estimated real machine settings can be applied to the succeeding manufacturing, so that the trial-and-error process which is carried out by the skilled workers will fall into disuse.