How the Formula Works
This calculator determines your drone’s total weight and center of gravity (CG) position based on component weights and positions.
Total Weight
Total Weight (g) = Σ (Component Weight)Center of Gravity
CG Position (mm) = Σ (Weight × Distance) / Σ (Weight)The CG is the weighted average of all component positions. Each component’s contribution is its weight multiplied by its distance from a reference point (center of frame).
Balance Check
The drone is considered balanced if the CG is within ±10% of the frame length from the ideal center.
Example
- Battery: 500g at -20mm (front)
- Camera: 200g at -30mm (front)
- Frame: 300g at 0mm (center)
Total = 500 + 200 + 300 = 1000g
Moment = (500×-20) + (200×-30) + (300×0) = -10000 + -6000 + 0 = -16000
CG = -16000 / 1000 = -16mm (slightly front-heavy)FAQs
1. Why is the CG important for drone flight?
A properly balanced drone is stable and predictable in flight. An off-center CG causes the drone to tilt, makes hovering difficult, and increases stress on motors.
2. Where should the CG be?
Ideally at the geometric center of the frame (where the FC is mounted). Many drones run slightly tail-heavy for better forward flight stability.
3. How do I measure component positions?
Measure from the center of the frame (0mm). Positions forward (or left) are negative, positions rear (or right) are positive.
4. What happens if my drone is unbalanced?
Flight performance suffers: the drone drifts in one direction, motors work harder on one side, battery drains faster, and gimbal/video quality degrades.
5. How do I fix an unbalanced drone?
Move the battery (the heaviest movable component) forward or backward to shift the CG. You can also reposition payloads or add small balance weights.
6. Does this calculator work for fixed-wing drones?
Yes, but for fixed-wing you should also consider the aerodynamic center, not just the CG. For multirotors, the geometric center is your target.
7. Can I use this to verify my AUW for regulations?
Yes. The total weight output helps determine your drone’s weight class for FAA/EASA registration requirements.