An infusion pump uses sensors, movable members and a control unit to determine tubing thickness in a tube-loading section of the pump. The infusion pump utilizes sensors, such as a pressure sensor, to record forces imparted by a tube undergoing no pressure, a single pressure, or a pressure sweep, to determine thickness. Using these values, the tubing wall thickness can be determined. The infusion pump can also compress a tube using a movable member of the pump and records the distance traveled by the movable member to compress fully the tube. Using this distance, the tubing wall thickness can be determined.