RC Airplane Power Calculator
What this calculator does
This calculator is useful for sport planes, trainers, scale aircraft, aerobatic models, and other propeller-driven electric RC airplanes. It estimates static thrust, pitch speed, current draw, input power, loaded voltage, loaded RPM, battery C demand, runtime, motor efficiency, and motor wattage use. Select catalog motors, ESCs, batteries, and airplane props where available, then use manual overrides for temperature, pressure, and throttle assumptions when needed. Example: before installing an APC 11x7E prop on a 4S setup, compare the expected current and thrust against the motor and ESC limits. The goal is not to replace wattmeter testing, but to avoid obviously mismatched setups before flight.
In practical terms: It estimates electric airplane prop setup performance so motor, prop, ESC, and battery choices can be compared before testing.
How to use it
Select or enter the motor, propeller, ESC, battery, and cell count. Review current, thrust, RPM, pitch speed, efficiency, and battery demand.
Example calculation
Check whether a 4S 5000mAh pack and APC 11x7E prop keep current within the ESC limit while still producing enough thrust.
FAQ
What does the Airplane Power Calculator estimate?
It estimates static thrust, current draw, wattage, loaded RPM, pitch speed, battery demand, runtime, motor efficiency, and motor wattage use.
Why can calculated RPM differ from a tachometer reading?
Real RPM depends on motor data accuracy, prop loading, timing, battery condition, cooling, and voltage sag. Use the calculator as a planning model and verify with real measurements.
Should I choose a prop based only on thrust?
No. Also check current, wattage, pitch speed, battery load, ESC headroom, and motor temperature. A high-thrust prop can overload the power system.
Why is motor efficiency useful?
Motor efficiency helps show how much input power is becoming useful mechanical output instead of heat. Lower efficiency usually means more thermal stress.