Performance setup utility
Prop slip calculator.
Compare theoretical propeller travel with measured GPS speed to establish a repeatable setup baseline.
01 / MEASURED INPUTS
Enter one test pass.
Use steady-state GPS speed and verified engine RPM from the same pass.
02 / CALCULATED RESULT
Setup snapshot.
13.4%
Calculated propeller slip
Theoretical speed121.2 mph
Measured speed105.0 mph
Prop shaft RPM4000
INTERPRETATION
Typical efficient performance range for many properly set-up planing boats.
FormulaTheoretical MPH = RPM × pitch ÷ gear ratio ÷ 1056Slip % = (theoretical speed − GPS speed) ÷ theoretical speed × 100
This calculator is an estimation and diagnostic aid, not setup or operating instruction. Follow manufacturer limits and consult a qualified marine professional before making changes.