A flow control device for controlling flow in a heating, ventilation, or air conditioning (HVAC) system is shown. The flow control device includes a valve body including an inlet path, an outlet path, a valve member, and a valve stem coupled to the valve member. The flow control device includes a first sensor configured to obtain pressure measurements within the valve body, a second sensor configured to obtain displacement measurements of the valve stem, and a controller including a processing circuit configured to determine a flowrate based at least on the pressure measurements from the first sensor and the displacement measurements from the second sensor.