Propeller Slip Calculator app for iPhone and iPad

Slip is the most misunderstood of all propeller terms, probably because it sounds like something undesirable. Slip is not a measure of propeller efficiency. Rather, slip is the difference between actual and theoretical travel resulting from a necessary propeller blade angle of attack. If the blade had no angle of attack, there would be no slip; but, of course, there would be no positive and negative pressure created on the blades and, therefore, there would be no thrust. Use this app to figure out what you theoretical top speed is, propeller slip, or what RPM you should be running while achieving your estimated top speed with a variable slip.