Not sure which propeller size to choose for your RC boat? Our RC Boat Propeller Size Calculator makes it simple to find the right prop size based on your motor and boat specifications. Just enter your motor’s KV rating, battery voltage, boat length, and type to get instant recommendations. Whether you’re building a speed demon or a scale model, this calculator helps you select the optimal propeller for maximum performance and efficiency.

RC Boat Propeller Size Calculator

Motor RPM per volt, usually listed in motor specs
Battery voltage under load (e.g., 3S = 11.1V)

This RC Boat Propeller Size Calculator helps RC boat enthusiasts select the optimal propeller size for their model boats. By considering motor specifications, boat characteristics, and intended use, it provides precise propeller recommendations for maximum performance.

RC Boat Propeller Size Calculator

Understanding Propeller Basics

Key Measurements

  • Diameter: Overall width of the prop
  • Pitch: Theoretical forward movement per rotation
  • Blade Count: Number of propeller blades
  • Surface Area: Total blade surface

Propeller Terminology

  • Leading Edge: Front edge of blade
  • Trailing Edge: Back edge of blade
  • Hub: Center mounting point
  • Rake: Blade tilt angle

Calculator Input Parameters

Motor KV Rating

  • What is KV?
    • RPM per volt rating
    • Lower KV = More torque
    • Higher KV = More speed
  • Common Ranges:
    • Racing: 2000-4000KV
    • Scale: 1000-2000KV
    • Utility: 800-1500KV

Battery Voltage

  • Common Configurations:
    • 2S (7.4V)
    • 3S (11.1V)
    • 4S (14.8V)
    • 6S (22.2V)
  • Voltage Impact:
    • Higher voltage = More power
    • Affects motor RPM
    • Influences prop size selection

Boat Length

  • Measurement Tips:
    • Measure hull length only
    • Exclude rudder/hardware
    • Use consistent units
  • Impact on Selection:
    • Larger boats = Larger props
    • Affects power requirements
    • Influences efficiency

Boat Type Selection

Sport/Racing

  • Characteristics:
    • High speed priority
    • Quick acceleration
    • Efficient design
  • Prop Requirements:
    • Smaller diameter
    • Higher pitch ratio
    • Performance focused

Scale Model

  • Characteristics:
    • Realistic appearance
    • Moderate speed
    • Balanced performance
  • Prop Requirements:
    • Scale-appropriate size
    • Medium pitch ratio
    • Realistic operation

Fishing/Utility

  • Characteristics:
    • Thrust priority
    • Reliable operation
    • Load carrying
  • Prop Requirements:
    • Larger diameter
    • Lower pitch ratio
    • Maximum thrust
Understanding Results

Understanding Results

Propeller Size Recommendation

Diameter Interpretation

  • Purpose:
    • Determines thrust
    • Affects efficiency
    • Impacts power draw
  • Adjustment Factors:
    • Water conditions
    • Load requirements
    • Speed goals

Pitch Understanding

  • Effects:
    • Speed potential
    • Acceleration
    • Motor load
  • Trade-offs:
    • Higher pitch = More speed
    • Lower pitch = Better acceleration
    • Balance needed

Performance Specifications

Motor RPM

  • Calculation basis
  • Operating range
  • Efficiency considerations

Theoretical Speed

  • Calculation method
  • Real-world factors
  • Performance expectations

Size Range Options

Diameter Range

  • Acceptable variations
  • Performance impact
  • Selection criteria

Pitch Range

  • Tuning options
  • Performance effects
  • Application specific

Frequently Asked Questions

Q: How accurate is the calculator?

A: The calculator provides theoretical recommendations. Fine-tuning may be needed based on specific conditions.

Q: Can I use a larger propeller?

A: Yes, but monitor motor temperature and power consumption carefully.

Q: How does water type affect selection?

A: Different water conditions may require prop size adjustments for optimal performance.

Q: When should I change my propeller?

A: Replace if damaged, or when performance significantly changes.

Enjoyed this RC Boat Propeller Size Calculator? Then be sure to check out our other guides.