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.

Current weight (lb)

Actual aircraft weight.

Published best glide (kt)

Best glide speed at the published weight.

Published weight (lb)

Reference weight for the published speed.

Compute the best glide speed for the current weight from a published reference. 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]

Best glide speed (kt)

Best glide speed at the current weight.

• 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.

• Vx Speed Calculator

  Compute the best angle-of-climb speed for the current weight from a published reference.

• Vy Speed Calculator

  Compute the best rate-of-climb speed for the current weight from a published reference.

• Max Range Airspeed Calculator

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