Stall Speed Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026The speed below which a wing stops flying
Stall speed is the minimum airspeed at which a wing can generate enough lift to support the aircraft's weight while operating at its maximum lift coefficient. Flying slower than this speed causes the airflow over the wing to separate, sharply reducing lift - a stall.
Worked example
For an aircraft weighing 10,000 N, with 16 m² of wing area, a maximum lift coefficient of 1.5, at sea-level air density (1.225 kg/m³):
Vstall = sqrt((2 x 10000) / (1.225 x 16 x 1.5)) = 26.08 m/s
Stall speed rises with weight and falls with wing area or lift coefficient - this is exactly why aircraft stall at a higher speed when heavily loaded, and why flaps (which increase effective wing area and lift coefficient) let aircraft fly and land safely at lower speeds.