What formula does the Stall Speed Calculator use?

It uses Vs = sqrt((2Wn) / (rho S CLmax)), where W is aircraft weight, n is load factor, rho is air density, S is wing area, and CLmax is maximum lift coefficient.

Can this calculator be used for real flight planning?

No. This calculator is for educational estimation only. Always use approved aircraft documentation, pilot operating handbooks, and certified flight data for real operations.

Stall Speed Calculator

Q: Why does stall speed increase in a turn?

In a coordinated turn, load factor increases. Stall speed rises with the square root of load factor.

How the Stall Speed Calculator Works

The Stall Speed Calculator estimates the speed at which an aircraft wing reaches the maximum lift coefficient and can no longer produce enough lift for the selected load condition.

Stall speed depends on aircraft weight, wing area, maximum lift coefficient, air density, and load factor.

Stall Speed Formula

The calculator uses:

Vs = √((2Wn) / (ρSCLmax))

where Vs is stall speed, W is aircraft weight in newtons, n is load factor, ρ is air density, S is wing area, and CLmax is the maximum lift coefficient.

Air Density Calculation

When pressure and temperature are used, the calculator applies:

ρ = P / (RT)

where P is pressure in pascals, R = 287.05 J/kg·K, and T is absolute temperature in kelvin.

Load Factor and Turns

Stall speed increases with load factor:

Vs,n = Vs,1g √n

In a coordinated level turn, load factor can be estimated from bank angle:

n = 1 / cos(bank angle)

How to Use the Calculator

Enter aircraft weight or mass.
Enter wing area.
Enter maximum lift coefficient CLmax.
Choose an air density method.
Enter load factor directly or calculate it from bank angle.
Click Calculate Stall Speed.

Example

Example values:

Mass = 1100 kg
Wing area = 16.2 m²
CLmax = 1.5
Air density = 1.225 kg/m³
Load factor = 1

These values give a basic 1g stall speed estimate. Increasing load factor increases the stall speed.

Important Limitations

Do not use this calculator for flight operations. Real aircraft stall speed depends on configuration, flap setting, contamination, bank angle, maneuvering, power, center of gravity, instrumentation, certification definitions, and manufacturer data.

Frequently Asked Questions

Why does stall speed increase with weight?

A heavier aircraft needs more lift. To create more lift at the same wing area and lift coefficient, it needs higher speed.

Why does stall speed increase in a turn?

A turn increases load factor. Stall speed rises with the square root of load factor.

Does altitude affect stall speed?

In true airspeed terms, lower air density increases stall speed. Indicated stall speed is a different operational concept and depends on aircraft instrumentation and certification.

Can I use this for RC aircraft?

It can be useful for educational RC aircraft estimates if weight, wing area, air density, and CLmax are known. Real behavior still depends on wing design and testing.