Prop Pitch Calculator

View Entire Guide or use our Pitch Calculator below: Prop Pitch Calculator Engine RPM engine RPM at cruise Cruise Airspeed (MPH) anticipated cruise airspeed Reduction Ratio (optional) :1 1.3 or 1.6 or 2.58 etc. (blank for none) Prop Length (optional) in inches Prop RPM Recommended Prop Pitch (assumes no "slip") Tip Speed (Ft/Sec) (if prop length given) Tip Speed Mach % (if prop length given) Recommended pitch is theroetical as it assumes no "slip". For very high pitch props (70"-80") the calculated Tip Speed has been adjusted 5%-6% to approximate true helix Tip Speed.  Otherwise circular Tip Speed is shown. Ideal Tip Speed varies depending on the H.P. per square ft of the prop disc. The efficiency of a propeller is reduced as the tip speed approaches the speed of sound.  Beyond 80% of the speed of sound, further increases in RPM has little affect on thrust.  Thus, it is important to keep tip speeds below 75%-80% of Mach.