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 landing weight.

Reference stall speed (kt)

Stall speed at the published weight.

Published weight (lb)

Weight at which the stall speed was published.

Compute final-approach speed as 1.3 times the stall speed scaled for actual weight. 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]

Vref (kt)

Final-approach target 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.

• Stall Speed Weight Correction Calculator

  Scale a published stall speed for actual weight using the square-root weight ratio.

• Minimum Sink Speed Calculator

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

• VFE Speed Calculator

  Compute the maximum flap extension speed as 1.6 times the stall speed.