The last of three principle computational steps to computing energy losses from an inflow pipe, through an access hole, and to the outlet pipe (in downstream to upstream order) is the calculation of exit loss. According to the HEC-22 (Third Edition) procedure, the relative Exit Loss () is evaluated independently for each incoming piped inflow to the structure. In fact, Exit Loss results are reported on the incoming pipes themselves.

If the pipe is contributing a plunging inflow to the structure, then the Exit Loss is not computed directly. The loss is effectively the relative difference between the energy level of the incoming plunging flow () and the previously solved Energy Grade Line (In) that is reported for the structure.

= Energy Grade Line (Ln) Reported on the Structure.

= Relative Exit Loss for the Inflow pipe.

In the case that the inflow pipe is not plunging, the Exit Loss () can be directly be computed.

= Exit Loss Coefficient = 0.4

= Velocity (Out) Reported on the Inflow Pipe.

= Gravity Constant