Our easy-to-use boat propeller calculator tool calculates the propeller pitch, engine gear ratio, engine revs, boat speed, propeller slip. All you need to do is give any of these 4 variables as input and click on the calculate button that gives you answers in seconds.

**Boat Propeller Calculator: **Looking for a free tool that calculates the boat propeller easily? Then use our free online tool that calculates the five variables easily and accurately. Just by giving inputs, you will get the output. And also we are providing steps to calculate the boat propeller manually. Read on to know the definitions, formulas.

Propeller slip delivers an indication of the efficiency with which a ship is traversing through the water. However, it is not to be confused with propeller efficiency.

A propeller slope can be understood by viewing the action of a screw. The pitch indicates the length that each rotation contributes to the extent to which the boat moves along on each rotation.

The gear ratio defines the number of drive shaft revolutions per propeller revolution. As such, if an engine has a gear ratio of 2:1, the machine drive shaft will turn twice for every propeller circle.

V = [RPM x PP x (1 − (PS/100))] / [GR x C]

PP = [V x GR x C] / [RPM x (1 − (PS/100))]

RPM = [V x GR x C] / [PP x (1 − (PS/100))]

PS = [1 − (V x GR x C) / (RPM x PP)] x 100

GR = [RPM x PP x (1 − (PS/100))] / [V x C]

Where:

V = speed

RPM = crankcase speed (rpm).

GR = number of revolutions the crankshaft needs to produce one revolution of the prop shaft.

PP = blade pitch (inches).

PS = index (as a percentage).

C = constant to convert inches-per-minute of revolution to boat speed V.

V (in mph), C = 1056.

V (in knots), C = 1215.2.

V (in kph), C = 656.

Follow the guidelines that are given below to calculate the boat propeller calculator easily.

- Take the inputs from the given problem and look into the problem what to find.
- Apply the formula which you need and substitute the values in it.
- Simplify the answer and you will get the answer easily.

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**1. How to use this boat propeller calculator?**

Simply give the inputs in the input fields and click on the calculate button that gives you the answer effortlessly.

**2. What is the best tool to calculate boat propeller?**

The boat propeller calculator is the best online tool that calculates the boat propeller.

**3. What is the best website that offers a boat propeller calculator?**

Arithmeticcalculator.com is the best website that offers a boat propeller calculator.