Quick Answer
Thrust is the pushing force a motor and prop produce. Torque is the twisting force the motor uses to spin that prop against air resistance. A thrust table shows real test data (thrust, current, and efficiency) at different throttle levels, so you can pick a motor with confidence instead of guessing from the KV number alone.
Stator Size and Why It Controls Torque
Every brushless motor has a part called the stator. It is the set of copper windings and metal plates inside the motor that create the magnetic field. Stator size is written as two numbers, like 2207 or 1404. The first two digits are the width in millimeters. The last two digits are the height.
A wider or taller stator can produce more torque, because it has more copper and more room for magnetic force. More torque means the motor can spin a bigger prop, or hold RPM steady under load instead of slowing down when the prop pushes back.
This is why two motors with the same KV can behave very differently. A 2207 motor and a 1404 motor might both be rated at 1900KV, but the 2207 has a much larger stator. It can handle a bigger prop and higher current without struggling or overheating.
Reading a Thrust Table
A thrust table is test data from a motor test stand. The stand holds the motor still, spins it at set throttle points, and measures results with a specific prop and battery voltage. Good thrust tables always state the exact prop and voltage used, because changing either one changes the results.
A typical thrust table includes:
| Throttle | Thrust (g) | Current (A) | Efficiency (g/W) |
|---|---|---|---|
| 25% | 180 | 3.2 | 9.6 |
| 50% | 420 | 9.8 | 7.4 |
| 75% | 680 | 18.5 | 6.4 |
| 100% | 850 | 26.0 | 5.6 |
Notice that efficiency (grams of thrust per watt of power) drops as throttle rises. This happens with almost every motor and prop combination. Near full throttle, you get less thrust for each extra watt you put in. This is why cruising at partial throttle is usually more efficient than flying at full throttle all the time.
What Each Column Actually Tells You
- Thrust (grams): How much lifting or pushing force the motor and prop produce at that throttle point. This is what fights gravity and drag.
- Current (amps): How much power the motor pulls from the battery. This tells you how hard your battery and ESC need to work, and how much heat to expect.
- Efficiency (grams per watt): How much thrust you get for the power spent. Higher numbers mean the setup does more work per unit of battery energy, which matters most for long-range and cinematic flying.
- Voltage and prop used: Not always a separate column, but always stated somewhere. Never compare thrust numbers from tables that used different props or voltages.
Thrust-to-Weight Ratio: What to Aim For
Thrust-to-weight ratio compares the total thrust your motors can produce (all of them added together, at full throttle) to the flying weight of the drone. A ratio of 2:1 means the drone could theoretically lift twice its own weight.
| Flying style | Suggested thrust-to-weight ratio |
|---|---|
| Cinematic, smooth filming | 2:1 to 3:1 |
| General freestyle | 3:1 to 5:1 |
| Racing and aggressive freestyle | 5:1 to 8:1 |
| Heavy-lift or cinelifter | 2:1 to 3:1 (with real safety margin) |
A higher ratio gives you sharper punch-outs and more control margin in wind, but it also means shorter flight times and more current draw. A lower ratio gives smoother, more efficient flight but less headroom if you need to recover from a dive or fly in gusty conditions.
Using Thrust Data to Choose a Motor
- Decide your flying style and target thrust-to-weight ratio from the table above.
- Estimate your all-up flying weight, including battery, camera and frame.
- Multiply your target ratio by the flying weight to get the total thrust you need at full throttle.
- Divide by the number of motors to get the thrust needed per motor.
- Search thrust tables for motors that reach that thrust figure at a throttle level below 100%, so you keep some headroom.
- Check the current draw at that thrust point against your ESC's rated current, with room to spare.
This method works far better than picking a motor because it "looks similar" to one in another build. Two frames of the same size can need different motors if their weight or prop choice is different. For help deciding motor size, ESC rating and prop size together, see how to match motors, ESCs and props.
Torque and Prop Size
A motor with strong torque can hold RPM steady even when a big prop pushes back hard against the air. A motor with weak torque will slow down under that same load, losing thrust and efficiency, and often overheating as it struggles.
This is why prop size and stator size are linked. Small stators (like 1404 or 1606) suit smaller props on 3-inch builds. Larger stators (like 2207 or 2306) suit the bigger props used on 5-inch and 7-inch builds. Fitting a large prop on a small-stator motor asks the motor to produce torque it was not built for, which usually leads to heat and poor performance. If your motors are already running hot, the guide on fixing hot FPV motors walks through common causes.