RC Boat Propeller Size Calculator

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 KV Rating:

Motor RPM per volt, usually listed in motor specs

Battery Voltage:

Battery voltage under load (e.g., 3S = 11.1V)

Boat Length (inches):

Boat Type:

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.

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

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.