For acceleration control with high performance, accurate velocity measurements assume a key role. In this paper, an approach to estimate velocity utilizing an encoder is proposed. Fundamental calculation method of the proposed method is M method with averaging. Though the resolution of M method is improved by averaging, detection of velocity changes delays and the system becomes insensitive to the disturbance. However, unlike simple M method with averaging, sensitivity to changes of velocity and disturbance is maintained in the proposed method. Simulation and experimental results are shown to verify the validity of the proposed approach.