Use this calculator for flight-planning study or a first-pass cross-check when all inputs describe the same aircraft, atmospheric condition, and phase of flight.

Stall speed (kt)

Stall speed of the aircraft.

Compute the maximum flap extension speed as 1.6 times the stall speed. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

VFE (kt)

Maximum flap extension speed.

• Do not use a generic calculator in place of the current aircraft flight manual, approved performance data, operating limitations, NOTAMs, weather, or regulations. Real performance changes with configuration, runway condition, altitude, temperature, wind, loading, and technique.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Cross-check the result against the aircraft flight manual or approved planning system, then apply the required safety margins. Keep signed wind, heading, altitude, speed, and fuel conventions explicit.

• VLE Speed Calculator

  Compute the maximum landing gear extended speed as 1.8 times the stall speed.

• VLO Speed Calculator

  Compute the maximum landing gear operating speed as 1.7 times the stall speed.

• Max Range Airspeed Calculator

  Estimate the best glide airspeed for maximum range as the square root of three times the minimum-sink speed.