Stall Speed Calculator

Summary

Calculate the minimum airspeed at which an aircraft can maintain level flight using weight, wing area, air density, and CLmax.

How it works

1. Enter the aircraft gross weight in pounds or kilograms.
2. Input the wing reference area (planform area) in square feet or square meters.
3. Specify air density — use the default sea-level value or enter altitude-adjusted density.
4. Enter the maximum lift coefficient (CLmax) for your configuration (clean, flaps down, etc.).
5. Click Calculate to get stall speed displayed in knots, mph, and m/s simultaneously.
6. Adjust any value to instantly see how configuration changes affect the stall speed.

Use cases

• Determine minimum approach speed for landing configuration.
• Compare stall speeds at sea level vs. high-altitude airports.
• Understand the effect of flap deployment on stall speed via CLmax changes.
• Calculate load-factor stall speed increase during banked turns.
• Verify performance handbook numbers against the lift equation.
• Educational demonstrations of how wing area and weight trade off.
• Preliminary sizing checks during aircraft conceptual design.
• Pilot ground school study and exam preparation.

Frequently Asked Questions