RC Boat Speed Calculator
Professional Speed Calculator for RC Electric & Nitro Boat Models
Our advanced RC boat speed calculator helps you instantly compute prop slip, propeller speed and top speed (MPH/Km/h). This comprehensive tool functions as both an RC boat prop speed and scale speed calculator, supporting brushless electric and nitro/gas boats with slip adjustment for real‑world accuracy.
Key Marine Considerations:- RC boat prop speed calculator - Calculate propeller efficiency and thrust
- RC boat scale speed calculator - Determine realistic scale performance
- Multi-motor configurations - Support for 1-4 motor setups with synchronized thrust
- Hull type coefficients - From 0.8 (displacement hulls) to 1.5 (high-speed hydroplanes)
- Propeller physics - Accounts for diameter, pitch and cavitation effects
- Real-world water conditions - Calibration for both calm and choppy waters
- Nitro/Gas specific factors - Fuel mixture ratios and cooling requirements
- Slip calibration - Use GPS speed data to back-calculate and tune slip for future predictions
Developed with input from international RC boat competitors, our algorithms have been tested across various hull types including deep-V, catamarans, and hydroplanes. The calculator adapts to your specific configuration whether you're running a scale model or competition racer.
RC Boat Speed Calculator Tool
Discover the secrets of RC boat speed - start here! Enter your boat parameters now to get personalized calculation results!
For RC boats, slip can be significant (30-45%)
Need help finding values? See how to get these parameters
Bookmark this useful calculator for quick access
Estimated Speed:
How to Calculate RC Boat Speed
RC Electric Boat Calculation Examples:
| Motor KV | Voltage | Prop Pitch | Slip | Speed (MPH/Km/h) |
|---|---|---|---|---|
| 1500KV | 11.1V (3S) | 1.4" | 30% | 15.5 / 24.9 |
| 2200KV | 7.4V (2S) | 1.2" | 30% | 12.9 / 20.8 |
| 1200KV | 14.8V (4S) | 1.6" | 30% | 18.8 / 30.3 |
RC Brushless Boat Speed Chart Table
RC Brushless Boat Speed Calculation Formula:
Speed(MPH) = Prop pitch(inches) × Motor kV × Battery Voltage × (1- Slip) ÷ 1056
Prop Speed Calculation: Prop Speed = Motor RPM × Propeller Pitch × (1 - Slip Factor)
Scale Speed Calculation: Scale Speed = Actual Speed ÷ Scale Factor (e.g., 1/10 scale = ÷10)
Example 1: 1500KV Motor with 3S Battery
- Motor KV: 1500
- Battery Voltage: 11.1V (3S)
- Propeller Pitch: 1.4 inches
- Slip Factor: 30%
Step-by-step calculation:
- Motor RPM = 1500 × 11.1 = 16,650 RPM
- Effective Pitch = 1.4 × (1 - 0.3) = 0.98 inches
- Prop Speed = 16,650 × 0.98 = 16,317 inches/minute
- Speed (MPH) = 16,317 ÷ 1056 = 15.45 MPH
- Speed (Km/h) = 15.45 × 1.609344 = 24.86 Km/h
Result: 15.45 MPH / 24.86 Km/h
Example 2: 1200KV Motor with 4S Battery
- Motor KV: 1200
- Battery Voltage: 14.8V (4S)
- Propeller Pitch: 1.6 inches
- Slip Factor: 30%
Step-by-step calculation:
- Motor RPM = 1200 × 14.8 = 17,760 RPM
- Effective Pitch = 1.6 × (1 - 0.3) = 1.12 inches
- Prop Speed = 17,760 × 1.12 = 19,891 inches/minute
- Speed (MPH) = 19,891 ÷ 1056 = 18.84 MPH
- Speed (Km/h) = 18.84 × 1.609344 = 30.32 Km/h
Result: 18.84 MPH / 30.32 Km/h
How to find these parameters? (Brushless Electric Boat)
- Motor KV: Check the motor can label, spec sheet, or product page.
- Battery Voltage: Use nominal LiPo voltage (2S ≈ 7.4V, 3S ≈ 11.1V, 4S ≈ 14.8V).
- Prop Pitch (inches): Find on propeller model number/spec, or manufacturer’s chart.
- Slip Factor (%): Start with 30–45% for boats; refine from GPS test data.
Tip: Record real GPS speed and back-calculate slip to tune future predictions.
RC Nitro/Gas Boat Calculation Examples:
| Engine RPM | Prop Pitch | Speed (MPH/Km/h) |
|---|---|---|
| 25,000 | 1.4" | 33.1 / 53.3 |
| 28,000 | 1.5" | 39.8 / 64.0 |
| 30,000 | 1.2" | 34.1 / 54.9 |
| 32,000 | 1.6" | 48.5 / 78.0 |
| 35,000 | 1.4" | 46.4 / 74.7 |
RC Nitro/Gas Boat Speed Chart Table
RC Nitro/Gas Car Speed Calculation Formula:
Speed (MPH) = (Motor RPM × Propeller Pitch) ÷ 1056
Example 1: .21 Engine with 1.4" Prop
- Engine RPM: 25,000
- Propeller Pitch: 1.4 inches
Step-by-step calculation:
- Prop Speed = 25,000 × 1.4 = 35,000 inches/minute
- Speed (MPH) = 35,000 ÷ 1056 = 33.14 MPH
- Speed (Km/h) = 33.14 × 1.609344 = 53.33 Km/h
Result: 33.14 MPH / 53.33 Km/h
Example 2: .28 Engine with 1.6" Prop
- Engine RPM: 32,000
- Propeller Pitch: 1.6 inches
Step-by-step calculation:
- Prop Speed = 32,000 × 1.6 = 51,200 inches/minute
- Speed (MPH) = 51,200 ÷ 1056 = 48.48 MPH
- Speed (Km/h) = 48.48 × 1.609344 = 78.02 Km/h
Result: 48.48 MPH / 78.02 Km/h
How to find these parameters? (Nitro/Gas Boat)
- Engine RPM: Refer to engine specs or measure with an optical/tachometer app after warm-up.
- Propeller Pitch (inches): Printed in prop model or listed by manufacturer/vendor.
Tip: Nitro performance varies with tune, temperature and fuel; measure after a consistent warm-up.
How to Use This Calculator:
- Enter your brushless motor's KV rating
- Input battery voltage (e.g. 11.1V for 3S LiPo)
- Enter prop size in millimeters
- Provide hull type factor (1.0-2.0)
- Get instant speed estimation
Pro Tips from Top Racers:
- "Understanding boat speed calculation starts with prop selection - a well-matched prop will give better performance than maximum speed." - RC Boat Champion
- "Use our RC boat speed calculator to validate manufacturer's recommended prop size, then adjust based on water conditions." - Professional RC Boater
- Lower KV motors (1000-2000) work better with larger props (40-60mm)
- Actual speed is typically 10-20% lower than calculated due to water resistance and hull drag
- For racing, target motor/engine temps of 60-70°C for optimal performance
- Always use an RC boat prop speed calculator to determine optimal propeller efficiency
- Regular speed calculations help identify performance issues and optimize your RC boat setup
- Scale speed calculations are essential for realistic performance in scale competitions