Abstract: Techniques are provided for improving pedometer readings. In some embodiments, motion data, such as acceleration data is detected, and a magnitude of the acceleration data, referred to as the modulus, is processed. The modulus is used to detect walking steps and running steps during a measurement. In some embodiments, a distance ran is calculated based on the detected running steps and an estimated running stride length, and a distance walked is calculated based on the detected walking steps and an estimated walking stride length. The estimated running and walking stride lengths are calculated based on various parameters associated with the acceleration data, population data, and user-specific data. Expended calories may be estimated based on the distance ran and walked. The distance analysis process further includes calibration techniques, including, for example, least squares simple regression, least squares multiple regression, and K-factor analysis.