Abstract: This disclosure describes, in part, techniques for calibrating positions of weight sensors for use in systems for tracking items within a facility. The techniques provide for receiving weight sensor data and image sensor data from sensors of a facility. The image sensor data is used to identify an event and corresponding data is identified from the weight sensor data to associate the weight sensor with a location identified with the event from the image data. The location may be associated with the weight sensor data for detecting and identifying items during subsequent events and interactions.