Drone Motor Calculator
Calculate motor thrust requirements for a drone based on weight, thrust-to-weight ratio, and number of motors. Determine the minimum thrust each motor must produce.
Typical: 2.0-3.0 (2.5 for good performance)
How to Use This Calculator
- Enter the total drone weight in grams (including battery, frame, electronics, payload).
- Enter the desired thrust-to-weight ratio (typically 2.0-3.0, higher for aggressive flying).
- Enter the number of motors (typically 4 for quadcopters, 6 for hexacopters, 8 for octocopters).
- The calculator displays the required thrust per motor and total thrust needed.
Motor Thrust Formula
Motor thrust requirements are calculated from weight and thrust-to-weight ratio:
Thrust per Motor = Total Thrust / Number of Motors
Example: 1000g drone, 2.5:1 ratio, 4 motors: Total thrust = 1000 × 2.5 = 2500g. Thrust per motor = 2500 / 4 = 625g. Each motor must produce at least 625g of thrust at full throttle.
Full Description
Selecting the right motors is crucial for drone performance. Motors must produce enough thrust to lift the drone, provide maneuverability, and handle payloads. The thrust-to-weight ratio determines flight characteristics: higher ratios enable more aggressive flying, better maneuverability, and the ability to carry payloads, while lower ratios limit performance but may improve efficiency.
A thrust-to-weight ratio of 2:1 means the motors can produce twice the drone's weight in thrust. This allows the drone to hover using 50% throttle, leaving 50% for maneuvering. Higher ratios (2.5:1, 3:1, or more) provide more headroom for aggressive flying, acrobatics, and payloads. Racing drones often use 4:1 or higher for maximum performance. The number of motors distributes the total thrust requirement—more motors mean less thrust per motor but provide redundancy.
This calculator helps you determine motor thrust requirements. Enter drone weight, desired thrust-to-weight ratio, and number of motors, and it calculates the minimum thrust each motor must produce. Use it when selecting motors, designing drones, or understanding thrust requirements. Remember that motor thrust depends on propeller selection, battery voltage, and motor specifications—check motor datasheets for actual thrust values at different voltages and prop sizes.
Frequently Asked Questions
How do I calculate motor thrust requirements?
Total thrust = Drone weight × Thrust-to-weight ratio. Thrust per motor = Total thrust / Number of motors. For example, 1000g drone, 2.5:1 ratio, 4 motors: Total = 1000 × 2.5 = 2500g. Per motor = 2500 / 4 = 625g.
What is a good thrust-to-weight ratio?
Minimum: 2:1 (can hover and fly, but limited performance). Good: 2.5:1 (comfortable flight with good maneuverability). Excellent: 3:1+ (aggressive flying, acrobatics, heavy payloads). Racing drones often use 4:1 or higher.
How do I choose the number of motors?
Common configurations: 4 motors (quadcopter - most common), 6 motors (hexacopter - more redundancy), 8 motors (octocopter - heavy lift, redundancy). More motors provide more thrust and redundancy but increase weight and complexity.
What affects motor thrust?
Motor thrust depends on: motor size (larger = more thrust), propeller size and pitch (larger props = more thrust), battery voltage (higher voltage = more RPM = more thrust), and motor KV rating (lower KV with larger props = more thrust).