How this calculator works
Lift is the component of aerodynamic force perpendicular to the incoming flow. Divide its magnitude by dynamic pressure and the reference planform area to obtain the magnitude of the lift coefficient. This calculator treats magnitudes; attach a sign separately when using an aerodynamic axis convention. Reverse modes assume a constant coefficient.
Formula
L = Cl rho v^2 A/2; Cl = 2L/(rho v^2 A).
Worked example
Lift of 120 N in rho = 1.2 kg/m3 at 10 m/s over 2 m2 gives Cl = 1. At 20 m/s, 480 N gives the same coefficient.
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Frequently asked questions
Which area should I enter?
Use the reference area associated with the lift data, usually wing planform area rather than wetted surface area.
Can lift point downward?
Yes. This magnitude calculator reports a nonnegative coefficient; a signed axis convention can assign a negative sign afterward.
Does this predict stall?
No. Stall changes the coefficient and requires measured or modelled aerodynamic data.