1. What is a Boat Prop Pitch Calculator?

Definition: This calculator determines the ideal propeller pitch based on boat speed, engine RPM, and propeller slip.

Purpose: It helps boat owners and mechanics select the proper propeller for optimal performance and fuel efficiency.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Pitch \) — Propeller pitch in inches
• \( S \) — Boat speed in miles per hour
• \( RPM \) — Engine revolutions per minute
• \( Slip \) — Propeller slip factor (decimal)

Explanation: The formula calculates how far the boat would move forward with one complete propeller revolution if there were no slip.

3. Importance of Proper Prop Pitch

Details: Correct propeller pitch ensures your engine operates in its optimal RPM range, improving performance, fuel efficiency, and engine longevity.

4. Using the Calculator

Tips: Enter your boat's speed at wide-open throttle, the corresponding engine RPM, and typical slip factor (default 0.12 for most boats).

5. Frequently Asked Questions (FAQ)

Q1: What is propeller slip?
A: Prop slip is the difference between theoretical and actual distance traveled per propeller revolution, expressed as a decimal (e.g., 0.12 = 12% slip).

Q2: What's a typical slip factor?
A: Most boats have 8-15% slip (0.08-0.15). High-performance boats may be lower, while heavily loaded boats may be higher.

Q3: Why 1056 in the formula?
A: This constant converts mph to inches per minute (1 mph = 1056 inches per minute).

Q4: How do I measure my boat's speed and RPM?
A: Use GPS for accurate speed measurement and your engine's tachometer for RPM at wide-open throttle.

Q5: What if my calculated pitch isn't available?
A: Choose the closest available pitch, or consult a propeller specialist about custom options.