Propeller Calc 3.2

This calculator provides calculations for essential parameters such as pitch, gear ratio, RPM, propeller slip, and speed. By entering any four of these variables, it computes the fifth. Users can select the desired output by toggling the switch to specify which parameter to calculate.

Pitch represents the theoretical forward movement of the propeller per revolution. In practice, each inch of the boat's contact with water generates drag, resulting in the propeller "slipping" relative to its theoretical movement. This discrepancy between expected and actual movement is referred to as slip.

Typically, slip values range from 5% to 20%, depending on specific operating conditions. A lower slip percentage does not necessarily indicate higher efficiency, as slip varies with load, speed, and other factors. It is important to consult with marine propulsion professionals to interpret these values accurately for your particular application.

Wishing you safe and enjoyable powerboating.