A system comprising a biometric monitoring device including a housing including a platform to receive at least one foot of the user, a body weight sensor to generate body weight data, processing circuitry to calculate user weight data which corresponds to the user's weight, using the body weight data, and communication circuitry to: (a) receive user identification data which identifies the user or a portable activity monitoring device, and (b) transmit the user weight data to data storage associated with the user identification data. The system further includes the portable activity monitoring device including a housing having a physical size and shape that is adapted to couple to the user's body, a sensor to generate sensor data, and communication circuitry to receive physiologic data which is based on the user weight data, and processing circuitry to calculate activity data using the sensor data and physiologic data.