RC Car Speed Calculator
Professional Top Speed Calculator for RC Electric & Nitro Car Models
Whether you're tuning a brushless electric racer or a nitro-powered scale model, our RC car speed calculator provides accurate speed predictions for all types of RC vehicles. This versatile tool helps you determine both maximum achievable speeds and realistic scale performance, making it perfect for competitive racing or casual driving.
Key Features and Applications:- Accurate speed predictions - Get reliable estimates for all RC car types
- Top speed calculation - Determine maximum achievable speeds
- Scale speed conversion - Calculate realistic performance for scale models
- Gear ratio optimization - Find the perfect setup for your track
- Power system matching - Select the right motor and battery combination
- Professional algorithms - Trusted by competitive racers worldwide
- Instant calculations - Get results in real-time as you adjust parameters
Built with real-world data from professional racing teams, our calculator delivers the most accurate speed predictions available. From weekend hobbyists to championship competitors, this tool helps you optimize your setup for any driving style or track condition.
RC Car Speed Calculator Tool
Ready to calculate your RC car's speed? Simply enter your vehicle's specifications below and get instant, accurate results for both electric and nitro models.
Need help finding values? See how to get these parameters
Bookmark this useful calculator for quick access
Estimated Speed:
How to Calculate RC Car Speed? - Complete Guide
RC Electric Car Speed Calculation Examples:
Calculating your RC car's speed depends on several key factors: motor specifications, gear ratios, and tire size. Our calculator takes all these variables into account to give you accurate predictions. Here are some common setups and their expected speeds:
| Motor KV | Voltage | Pinion | Spur | Internal Ratio | Tire (in) | Speed (MPH/Km/h) |
|---|---|---|---|---|---|---|
| 2200 | 11.1 (3S) | 18 | 54 | 2.6 | 2.6 | 43.3 / 69.7 |
| 3500 | 7.4 (2S) | 20 | 80 | 2.6 | 2.2 | 34.7 / 55.8 |
| 1900 | 14.8 (4S) | 16 | 50 | 2.85 | 3.0 | 48.9 / 78.7 |
| 2650 | 11.1 (3S) | 22 | 72 | 2.85 | 2.4 | 45.5 / 73.2 |
| 3000 | 7.4 (2S) | 19 | 76 | 2.5 | 2.6 | 39.9 / 64.2 |
RC Electric Car Speed Chart Table
RC Electric Car Speed Calculation Formula
Motor RPM = KV × Voltage;
FDR = (Spur ÷ Pinion) × Internal Ratio;
Wheel RPM = Motor RPM ÷ FDR;
Speed (MPH) = Wheel RPM × Tire Diameter (in) × 3.14159 × 60 × 1.578 ÷ 100000
Top Speed Calculation: Top Speed = Maximum achievable speed under ideal conditions
Scale Speed Calculation: Scale Speed = Actual Speed ÷ Scale Factor (e.g., 1/10 scale = ÷10)
Example 1: 2200KV Motor with 3S Battery
- Motor KV: 2200
- Battery Voltage: 11.1V (3S)
- Pinion Gear Teeth: 18T
- Spur Gear Teeth: 54T
- Internal Gear Ratio: 2.6
- Tire Diameter: 2.6 inches
Step-by-step calculation:
- Motor RPM = 2200 × 11.1 = 24,420 RPM
- FDR = (54 ÷ 18) × 2.6 = 7.8
- Wheel RPM = 24,420 ÷ 7.8 = 3,131 RPM
- Speed (MPH) = 3,131 × 2.6 × 3.14159 × 60 × 1.578 ÷ 100000 = 43.3 MPH
- Speed (Km/h) = 43.3 × 1.609344 = 69.7 Km/h
Result: 43.3 MPH / 69.7 Km/h
Example 2: 3500KV Motor with 2S Battery
- Motor KV: 3500
- Battery Voltage: 7.4V (2S)
- Pinion Gear Teeth: 20T
- Spur Gear Teeth: 80T
- Internal Gear Ratio: 2.6
- Tire Diameter: 2.2 inches
Step-by-step calculation:
- Motor RPM = 3500 × 7.4 = 25,900 RPM
- FDR = (80 ÷ 20) × 2.6 = 10.4
- Wheel RPM = 25,900 ÷ 10.4 = 2,490 RPM
- Speed (MPH) = 2,490 × 2.2 × 3.14159 × 60 × 1.578 ÷ 100000 = 34.7 MPH
- Speed (Km/h) = 34.7 × 1.609344 = 55.8 Km/h
Result: 34.7 MPH / 55.8 Km/h
RC Nitro/Gas Car Speed Calculation Examples:
| Engine RPM | Pinion | Spur | Internal Ratio | Tire (in) | Speed (MPH/Km/h) |
|---|---|---|---|---|---|
| 30,000 | 18 | 54 | 2.6 | 2.6 | 29.7 / 47.8 |
| 32,000 | 20 | 80 | 2.6 | 2.2 | 20.1 / 32.4 |
| 28,000 | 16 | 50 | 2.85 | 3.0 | 28.0 / 45.1 |
| 35,000 | 22 | 72 | 2.85 | 2.4 | 26.8 / 43.1 |
| 38,000 | 19 | 76 | 2.5 | 2.8 | 31.7 / 51.0 |
RC Nitro/Gas Car Speed Chart Table
RC Nitro/Gas Car Speed Calculation Formula:
Motor RPM = Engine RPM
FDR = (Spur ÷ Pinion) × Internal Ratio
Wheel RPM = Motor RPM ÷ FDR
Speed (MPH) = Wheel RPM × Tire Diameter (in) × 3.14159 × 60 × 1.578 ÷ 100000
Example 1: .21 Engine with 18T/54T Gears
- Engine RPM: 30,000
- Pinion Gear Teeth: 18T
- Spur Gear Teeth: 54T
- Internal Gear Ratio: 2.6
- Tire Diameter: 2.6 inches
Step-by-step calculation:
- Motor RPM = Engine RPM = 30,000
- FDR = (54 ÷ 18) × 2.6 = 7.8
- Wheel RPM = 30,000 ÷ 7.8 = 3,846 RPM
- Speed (MPH) = 3,846 × 2.6 × 3.14159 × 60 × 1.578 ÷ 100000 = 29.7 MPH
- Speed (Km/h) = 29.7 × 1.609344 = 47.8 Km/h
Result: 29.7 MPH / 47.8 Km/h
Example 2: .28 Engine with 20T/80T Gears
- Engine RPM: 32,000
- Pinion Gear Teeth: 20T
- Spur Gear Teeth: 80T
- Internal Gear Ratio: 2.6
- Tire Diameter: 2.2 inches
Step-by-step calculation:
- Motor RPM = Engine RPM = 32,000
- FDR = (80 ÷ 20) × 2.6 = 10.4
- Wheel RPM = 32,000 ÷ 10.4 = 3,077 RPM
- Speed (MPH) = 3,077 × 2.2 × 3.14159 × 60 × 1.578 ÷ 100000 = 20.1 MPH
- Speed (Km/h) = 20.1 × 1.609344 = 32.4 Km/h
Result: 20.1 MPH / 32.4 Km/h
How to Use This Calculator:
- Enter your brushless motor's KV rating
- Input battery voltage (e.g. 11.1V for 3S LiPo)
- Enter pinion and spur gear teeth counts
- Provide your tire diameter in mm
- Get instant speed estimation
How to find these parameters?(Electric Car)
- Motor KV: Check your motor label/spec sheet or product page.
- Battery Voltage: Look at your LiPo pack cell count. 2S ≈ 7.4V, 3S ≈ 11.1V, 4S ≈ 14.8V.
- Pinion Gear Teeth: Count the teeth on the small motor gear (pinion), or read the printed number.
- Spur Gear Teeth: Count the teeth on the large spur gear, or read the printed number.
- Internal Gear Ratio: Find it in your chassis manual or manufacturer’s website (e.g., 2.6 for many 1/10 4WD).
- Tire Diameter (inches): Measure the diameter with a caliper/ruler, then convert to inches if needed.
Tip: If you changed pinion/spur, update both the teeth counts and recalc FDR. Using exact tire diameter (measured) gives the most accurate result.
How to find these parameters? (Nitro/Gas Car)
- Engine RPM: Refer to the engine spec sheet or data from a tachometer app/sensor after break-in.
- Clutch Engagement: Usually listed by manufacturer; otherwise estimate from manual or telemetry logs.
- Pinion/Spur Teeth: Count teeth on each gear or read the printed number on the gear.
- Tire Diameter (mm): Measure with calipers across the tire at ride height.
- Internal Gear Ratio (if applicable): Check the vehicle manual or brand website for your model.
Tip: Real nitro performance varies with tune, temperature, altitude and fuel. Measure after a full warm-up for the most representative numbers.
Pro Tips from Top Racers:
- "Gearing is everything - a well-geared slow car will beat a poorly-geared fast car every time." - Ryan Lutz, 5-time IFMAR World Champion
- "Start with manufacturer's recommended gearing, then make small adjustments one tooth at a time." - Ty Tessmann
- High KV motors (3000+) work best with smaller pinions (12-15T) to prevent overheating
- Real-world speed is usually 10-15% lower than calculated due to drivetrain losses and tire slip
- For optimal racing performance, keep motor temperatures between 65-75°C
- Use speed calculations to identify performance bottlenecks and optimize your setup
- Scale speed calculations help achieve realistic performance in scale competitions