Stall Speed Calculator


About Stall Speed Calculator (Formula)

A Stall Speed Calculator is an essential tool in aviation used to determine the minimum speed at which an aircraft can maintain level flight. Stall speed is a critical parameter for pilots and aircraft designers as it represents the lowest airspeed at which the wings generate sufficient lift to keep the aircraft airborne without descending uncontrollably. Falling below this speed can lead to an aerodynamic stall, a potentially dangerous situation where the aircraft loses lift and may start to descend or lose control.

The formula for calculating the stall speed of an aircraft is as follows:

Stall Speed (Vs) = √((2 * Weight) / (Air Density * Wing Area * Coefficient of Lift * Stall Margin))


  • Stall Speed (Vs) is the minimum speed at which the aircraft can maintain level flight, typically measured in knots or feet per second.
  • Weight is the total weight of the aircraft, including passengers, cargo, and fuel, measured in pounds or kilograms.
  • Air Density represents the density of the air at the given altitude and is typically measured in slugs per cubic foot or kilograms per cubic meter.
  • Wing Area is the total surface area of the aircraft’s wings, measured in square feet or square meters.
  • Coefficient of Lift is a dimensionless value that quantifies the lift characteristics of the aircraft’s wings at a specific angle of attack.
  • Stall Margin is a safety factor used to ensure a margin of safety above the calculated stall speed.

It’s important to note that the stall speed of an aircraft can vary depending on several factors, including aircraft configuration, altitude, and weight. Pilots must be aware of the specified stall speed for their specific aircraft and operating conditions to ensure safe flight.

Stall Speed Calculators are invaluable for pilots during flight planning and operation. By using this tool, pilots can ensure that they maintain a safe margin above the stall speed to prevent stalling, especially during takeoff, landing, or maneuvers. Aircraft designers also use these calculations to optimize wing design for safe and efficient flight performance.