Enter the weight of the aircraft, the coefficient of lift, the wing surface area, and the density of the air into the calculator to determine the takeoff velocity.

## Takeoff Velocity Formula

The following equation is used to calculate the Takeoff Velocity.

V = SQRT (2*m*g / (CL*A*d))
• Where V is the Takeoff Velocity (m/s)
• m is the mass of the aircraft (kg)
• g is the acceleration due to gravity (9.81m/s^2)
• CL is the coefficient of lift
• A is the surface area of the wings (m^2)
• d is the density of the air (kg/m^3)

To calculate the takeoff velocity, divide the product of 2 times the mass times g by the product of the coefficient of lift, the surface area of the wings, and the density of the air, then take the square root of the result.

## What is a Takeoff Velocity?

Definition:

A takeoff velocity describes the speed at which the lift force is equal to the mass of the aircraft.

## How to Calculate Takeoff Velocity?

Example Problem:

The following example outlines the steps and information needed to calculate Takeoff Velocity.

First, determine the mass of the aircraft. In this example, the mass is found to be 4000kg.

Next, determine the coefficient of lift. For this problem, the coefficient of lift is found to be .85.

Next, determine the surface area of the wings. In this case, the area is measured to be 100 m^2.

Next, determine the density of the air. For this, the air density is 1.225 kg/m^3.

Finally, calculate the Takeoff Velocity using the formula above:

V = SQRT (2*m*g / (CL*A*d))

V = SQRT (2*4000*9.81 / (.85*100*1.225))

V = 27.453 m/s