A simple model for the flow of plasma from the ends of a theta pinch is used to calculate the steady state plasma loss rate. The flow is similar to hydrodynamic flow in a flexible nozzle; special attention must be paid to the conditions in the "throat" of the nozzle. The plasma loss rate is then a function of the plasma parameters and the mirror ratio of the coil—when this is appropriately defined. Graphs and convenient formulas for the loss are provided.