How FIT™ is your showerhead?

Flow Impact Intensity (FIT Value) is a measure of a showerhead's overall strength of flow delivery.

The Flow Strength of a showerhead can be determined by a physical measure of the power that it generates, when tested on a modified *Hookian-Young's Modulus Spring Scale System. The FIT value measured on the system is then divided by the actual amount of water that it uses in order to generate that measurement, with the result being the showerhead's overall performance value relative to the amount of water that it consumed during the  test procedure. The higher the number, the better the performance (P) of the showerhead relative to its strength of delivery, divided by the actual amount of water that it characteristically consumes, in order to complete its everyday mode of operation. Obviously, some showerheads will perform better than others due to the overall efficiency of their design and inherent flow strength capabilities. 

Showerheads lacking in a High Flow Impact Value must use a much higher flow volume delivery (V_R), in order to compensate for the lack of power. When this happens the showerhead's overall performance value (P) falls off dramatically. This can be readily calculated using the formulae shown below, where: