In daily life, walking is one of the most energy consumed activity. There are many researches' focuses on energy expenditure estimation using GPS and 3-axis accelerometer for location tracking and activity monitoring. However, in the case of walking on a slope, GPS location tracking method and 3-axis accelerometer method are failed to estimate the energy consumption while walking on a slope. In this paper, the authors combine the information of GPS in smart phone, the information of foot-mounted IMU and also the slope information from Google elevation database to estimate activity energy expenditure. Energy expenditure in static movement is calculated using accelerometer data. Therefore, the energy expenditure calculator is capable to calculate energy expenditure in static movement and also in dynamic movement.