What Is Thrust-to-Weight Ratio?
Thrust-to-weight ratio (TWR) compares the total pushing force of your motors with the weight of the whole drone. A TWR of 2 means the motors can lift twice the drone's weight. It's the single best indicator of how a drone will feel in the air.
TWR = (max thrust per motor × number of motors) ÷ all-up weight
How to Read Your Result
| Ratio | What it feels like | Typical use |
|---|---|---|
| Under 1.5 | Sluggish, unsafe in wind | Not recommended |
| 1.5 to 2.5 | Smooth, efficient, stable | Camera, mapping, payload |
| 2.5 to 5 | Lively and responsive | Sport flying, cinematic FPV |
| 5 to 8 | Very punchy | Freestyle FPV |
| Over 8 | Extreme acceleration | Racing |
Hover Throttle
The calculator also estimates hover throttle as weight divided by thrust. A drone at 50 percent hover throttle has plenty in reserve. Above about 65 percent, it will struggle in wind and drain batteries quickly. This is a simplified estimate, since real thrust doesn't rise perfectly in line with throttle, but it's a good sanity check.
Worked Example
A 650 g freestyle quad with four motors making 1,600 g each has 6,400 g of thrust and a TWR of about 9.8. That's racing territory. Add a 150 g action camera and it drops to 8, still very fast. Check what extra load you can carry with the payload capacity calculator.
Not sure which flying style suits you? Read camera drone vs FPV drone or see the Skysdrone FPV drone.
FAQ
Frequently Asked Questions
What is a good thrust-to-weight ratio for a drone?
Around 2:1 for camera and mapping drones, 3:1 to 5:1 for sport flying and cinematic FPV, and 7:1 or more for racing and freestyle quads.
Can a drone fly with a thrust-to-weight ratio of 1?
Technically it could barely lift off, but it would have no power to climb, steer or recover. Anything under about 1.5:1 is unsafe.
How do I find my motor thrust?
Use the manufacturer thrust table for your exact motor, propeller and battery voltage. Thrust changes a lot with propeller size and voltage.
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