Propeller Pitch Calculator

Calculate optimal prop pitch based on engine RPM and desired speed

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Propeller Analysis

Recommended Pitch Change --
Optimal Pitch --
RPM Difference --
Current Prop Shaft RPM --
Theoretical Speed --
Estimated Slip --

Pitch Change Effects

Change RPM Effect Best For
+2" pitch -300-400 RPM Too much RPM, more speed
+1" pitch -150-200 RPM Slight over-rev
Correct At rated WOT Optimal performance
-1" pitch +150-200 RPM Can't reach WOT
-2" pitch +300-400 RPM Heavy load, bad hole shot

About Propeller Pitch

Pitch Definition: Propeller pitch is the theoretical distance (in inches) the propeller would move forward in one revolution if there were no slip.

Rule of Thumb: Each inch of pitch change typically results in 150-200 RPM change. Increasing pitch lowers RPM and vice versa.

Proper Propping: Engine should reach manufacturer's rated WOT RPM range when fully loaded and trimmed for best speed. Under-propping causes over-revving; over-propping causes lugging.

Slip: Typical propeller slip is 10-20% for efficient props, higher for workboat props. Less slip generally means better efficiency.