How to Calculate for the Lift of a Kite

Find the area of the kite. This can be done by using commonly known formulas for that geometric shape. If the kite is a rectangle, the area of the kite can be found by multiplying the width and the length of the kite together. As an example, if the width is 0.15 meters (m) and the length is 0.20 m, the area of a rectangular kite is 0.03 meters squared (m^2).

Square the value of the wind velocity. For example, if the wind speed is known to be 5 meters per second (m/s), squaring this result gives 25 meters squared per second squared (m^2/s^2).

Determine the lift coefficient of the kite. While difficult to find experimentally, a good approximation of this value can be found by multiplying the angle of elevation of the kite (i.e., the angle of the kite relative to the ground) in radians by 2 and the constant pi. For example, if the angle of elevation is 45 degrees, convert this to radians by multiplying by the constant pi (i.e., 3.14159...) and dividing by 180. This gives 0.785. Multiplying this value by 2 and pi gives 4.93 as the angle of elevation.

Find the density of air. You may want to assume the value is the density of air at sea level, which is 1.23 kilograms per meter cubed (kg/m^3), although it varies based on elevation.

Multiply the values from each of the previous steps above together. In the example used, you would multiply the values 0.03 m^2, 25 m^2/s^2, 4.93 and 1.23 kg/m^3 together. This gives 4.55 newtons (N).

Multiply the result from the previous step by 0.5. This gives the lift of the kite. In our example, 4.55 N multiplied by 0.5 gives 2.27 N, which is the value of the lift in our example.