A flow indication system for a central tire inflation system is provided. The flow indication system provides a venturi in fluid communication with the conduit providing air to a tire. A pressure reading is taken at the inlet and throat of the venturi and the air flowing through the venturi is calculated based on the pressure differential. According to some embodiments, the pressure readings are provided to a microcontroller that uses a table and interpolation algorithms to calculate the flow of the air flowing through the venturi, such as the mass of air in a given unit of time (grams/second for example). In one embodiment, two separate pressure sensors are coupled to different ends of a narrowed orifice that causes a pressure change in the flow as flow rate increases in the throat of the sensor. This pressure change is then used to calculate a proportional flow that can then be broadcast to various parties instead of an on/off reading.