As researchers explore the benefits of using pedometers to assess physical activity they are discovering that intensity of physical activity may be estimated from steps per minute (SPM). The purpose of this study was to determine the SPM and kilocalories (kcals) expended associated with moderate physical activity in middle school students (12 - 14 years old). Methods: Ninety-three (49 boys, 44 girls) middle school youth between the ages of 12 and 14, walked on a treadmill at four different speeds (4.0, 4.8, 5.64, and 6.4 km/h) for three minutes at each speed. Each participant wore a pedometer in order to obtain their steps per minute and a heart rate monitor to record their heart rate level during each test speed. Results: Moderate physical activity was reached, on average, by girls and boys at 122 SPM (5.64 km/h) and 115 SPM (4.8 km/h), respectively. At this SPM rate boys and girls expended 232.55 kcals and 176.66 kcals per hour. This study augments previous studies that explored ways to assess activity levels using SPM calculations.