Tools
FPV motor calculator
Free all-up weight (AUW) calculator for FPV drones. Estimate hover throttle, thrust-to-weight, current and speed for quadcopter, hexacopter and octocopter builds using published motor test curves and common 5, 7 and 10 inch props.
Airframe
Quad frame
Motor
Prop
All-up weight
1200 g
Thrust / weight
—
2.0 is a common FPV hover floor
—
Hover throttle
Est. level speed
—
Level flight at this AUW
Pitch speed
—
Helix speed at this load
- Hover power
- —
- Hover current
- —
- Max AUW @ 2:1
- —
- Motors
- 4
Thrust / motorPower / motorDotted = estimated prop
Measured points are the motor maker’s in-house test on the listed prop and cell count. Other props, hex/octo, and speed use a browser estimate. Not a wind-tunnel measurement. Hot/high density altitude is worse than these sea-level numbers.
Level speed solves T² = W² + D² with parasite drag D = ½ρV²CDA. Thrust is T = T₀(n/n₀)²(1 − V/nP) from blade-element CT versus J = V/(nD) (McCormick, Aerodynamics of V/STOL Flight). RPM n sits on the motor speed–torque line between static full-load n₀ and no-load KV × 3.7 V × cells. Heavier AUW raises required thrust, so n — and pitch speed nP — drop. Sea-level ρ = 1.225 kg/m³.
How this FPV motor calculator works
Enter all-up weight, pick a motor from the Warfare Labs Shop catalogue, a propeller, and a frame. The tool interpolates the motor’s published thrust and power curve when the prop matches the test prop. A different prop is scaled in the browser and marked as an estimate. Estimated level speed and pitch speed both fall as AUW rises. Defaults to a quadcopter (4 motors); hex and octo are one click.
Motors in the calculator
- QPT 2807 KV1300 Brushless Motor (QPT-2807) — 6S · GF 7040 prop · 25 °C
- QPT 2807 KV1300 Brushless Motor — 4-Pack (QPT-2807-4PK) — 6S · GF 7040 prop · 25 °C
- QPT 3115 KV900 Brushless Motor (QPT-3115) — 6S · G 10×5×3 prop · 25 °C
- QPT 3115 KV900 Brushless Motor — 4-Pack (QPT-3115-4PK) — 6S · G 10×5×3 prop · 25 °C
Common FPV propellers
5 inch
- Gemfan Hurricane 51499 — 5.1×4.99×3
- Gemfan Hurricane MCK 51366 — 5.0×2.8×3
- Gemfan Flash 5152 — 5.1×5.2×3
- Gemfan Flash 5149 — 5.1×4.9×3
- HQProp FlowerPig — 5.1×2.9×3
- DalProp SpitFire T5146.5 — 5.1×4.65×3
- HQProp 5.1x3.6x3 — 5.1×3.6×3
- HQProp 5x4x6 — 5.0×4.0×6
- Gemfan Hurricane 51433 — 5.1×3.5×3
7 inch
- Gemfan GF 7040 — 7×4.0×3
- Gemfan Flash 7042 — 7×4.2×2
- Gemfan LR 7035 — 7×3.5×2
- Gemfan Hurricane 7035 — 7×3.5×3
- Gemfan 7037 Cinelifter — 7×3.7×3
- Gemfan Hurricane 7050 — 7×5.0×3
- HQProp DP 7x4x3 — 7×4.0×3
- HQProp 7.5x3.7x3 — 7.5×3.7×3
10 inch
- V-Prop 10x5x3 — 10×5.0×3
- Gemfan 1050 Cinelifter — 10×5.0×3
- Gemfan MR 1045 — 10×4.5×2
FPV motor calculator FAQ
What is AUW on a drone?
All-up weight (AUW) is the flying mass of the aircraft: frame, motors, props, battery, camera and payload. This calculator uses AUW in grams to estimate hover throttle and thrust-to-weight.
What thrust-to-weight ratio do I need for FPV?
About 2:1 is a common FPV hover floor. Cinematic or payload builds often fly closer to 1.5:1. Freestyle and racing sit higher. The gauge marks 2.0 as a reference, not a rule.
Does this FPV motor calculator work for quad, hex and octo?
Yes. It defaults to a quadcopter (4 motors). You can switch to hexacopter (6) or octocopter (8). Quad frame layouts include True-X, Deadcat, Stretch-X, Wide-X, H and Plus.
Are the thrust numbers from a wind tunnel?
No. When the prop matches the motor maker’s test prop, the curve is that published in-house test. Other props and estimated level speed are a browser model, not a wind-tunnel measurement.
Does all-up weight change top speed?
Yes. Heavier AUW spends more thrust holding the aircraft up, so motors stay more loaded, RPM drops, and both estimated level speed and pitch speed (helix speed nP at that RPM) fall.