Drone Motor Calculator

Your details

RPM per volt (unloaded). Stamped on the motor stator or in the spec sheet. Common values: 2400 KV for 5" FPV, 1000 KV for 7" long-range, 300-500 KV for large cinematography builds.
KV
The rated maximum continuous current from the motor datasheet. Used to estimate max power and validate ESC selection.
A
Number of motors/propellers on the frame.
The first number in the propeller designation (e.g. 5 in a "5045" prop). For metric props, convert: 1 in = 2.54 cm.
in
The second number in the designation (e.g. 4.5 in a "5045" prop). Pitch is the theoretical distance the prop moves forward per revolution.
in
More blades increase thrust at a given diameter but also increase drag, reducing efficiency. Bi-blades are the efficiency standard; tri-blades trade some efficiency for a smoother power band.
Number of LiPo cells in series. Each nominal cell is 3.7 V; full charge is 4.2 V/cell. Higher S count raises voltage, which raises RPM proportionally.
Total rated capacity of the pack. The flight-time estimate uses 80 % of this figure to protect cell health.
mAh
Continuous discharge rate multiplier. Max current the pack can safely deliver = C-rating x capacity (Ah). A 1300 mAh 75C pack can supply up to 97.5 A continuously.
C
All-up weight including battery, camera, payload - everything that must be lifted. Weigh your completed build or use a realistic estimate.
g
Thrust per motorRacing / acrobatic
6,077g

Static thrust each motor produces at full throttle (sea-level air)

Total thrust24,310g
Thrust-to-weight ratio (TWR)54.02
Hover throttle13.6%
Hover current (total)1A
Estimated hover time55min
Max battery current97.5A
Hover efficiency30.4g/W
RPM at full throttle35,482RPM
Prop tip speed235.9m/s
Max power per motor504W
Battery safetyDanger: C-rating too low for full throttle
54.02 :1
Under-powered<2Minimum2-3Balanced3-5High-perf5-8Racing8+

TWR of 54.02 is strong - this build has plenty of power for aggressive flying.

  • Each motor produces approximately 6077 g of static thrust at full throttle using a 5" prop on 4S.
  • Hover throttle of 13.6 % indicates very efficient hover.
  • Estimated hover endurance is about 55.0 minutes on this battery.
  • Tip speed of 236 m/s exceeds Mach 0.5 (170 m/s) - compressibility losses reduce thrust. Consider a lower-KV motor or smaller diameter prop.
  • Hover efficiency of 30.4 g/W is excellent (target: 5+ g/W for FPV, 8+ g/W for long-range).

Next stepVery high TWR can make the drone twitchy. Consider a heavier payload or a lower-KV/smaller-prop combination for smoother flight.

 = Powered by OnlyCalculators