Propeller Pitch Calculator
Propeller Pitch
Find the optimal propeller pitch for your boat engine based on current RPM, desired RPM, and existing propeller specifications for best performance.
Formula
RPM Change Per Inch of Pitch = ~200 RPM; New Pitch = Current Pitch - (RPM Difference / 200); Theoretical Speed = (RPM x Pitch) / 1056; Prop Slip = (Theoretical Speed - Actual Speed) / Theoretical Speed x 100
Frequently Asked Questions
How does propeller pitch affect performance?
Lower pitch increases acceleration and RPM but reduces top speed. Higher pitch increases top speed and fuel efficiency at cruise but reduces hole shot and acceleration. Each inch of pitch changes RPM by approximately 150 to 200.
What is propeller slip?
Prop slip is the difference between theoretical speed based on pitch and RPM versus actual speed. Normal slip is 10 to 20 percent. High slip may indicate a worn or incorrectly sized propeller.
How do I know if my prop pitch is correct?
Your engine should reach the manufacturer recommended wide-open-throttle RPM range with your normal load. If WOT RPM is below the range, reduce pitch. If above, increase pitch.