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.

Minimum sink speed (kt)

Minimum-sink airspeed of the glider.

Estimate the maximum-endurance airspeed of a glider, which equals the minimum-sink 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]

Max endurance speed (kt)

Airspeed for maximum endurance.

• 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.

• Max Range Airspeed Calculator

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

• Minimum Sink Speed Calculator

  Compute the speed for minimum sink rate scaled by the fourth-root weight ratio.

• Ground Speed Calculator

  Compute ground speed from true airspeed and wind using the wind triangle.