Using Bernoulli's equation, the pressure coefficient can be further simplified for potential flows (inviscid, and steady):
where: 
:  is the flow speed at the point at which pressure coefficient is being evaluated
:  is the Mach number, which is taken in the limit of zero
:  is the flow's stagnation pressure
This relationship is valid for the flow of incompressible fluids where variations in speed and pressure are sufficiently small that variations in fluid density can be neglected. This assumption is commonly made in engineering practice when the Mach number is less than about 0.3.
*  of zero indicates the pressure is the same as the freestream pressure.
*  of one corresponds to the stagnation pressure and indicates a stagnation point.
* the most negative values of  in a liquid flow can be summed to the cavitation number to give the cavitation margin. If this margin is positive, the flow is locally fully liquid, while if it is zero or negative the flow is cavitating or gas.
Locations where  are significant in the design of gliders because this indicates a suitable location for a "Total energy" port for supply of signal pressure to the Variometer, a special Vertical Speed Indicator which reacts to vertical movements of the atmosphere but does not react to vertical maneuvering of the glider.
In an incompressible fluid flow field around a body, there will be points having positive pressure coefficients up to one, and negative pressure coefficients including coefficients less than minus one.