Enter the planform (reference) area, chord length, and span of a constant-chord (rectangular) wing into the calculator to determine the missing variable.

Wing Planform (Reference) Area Calculator

Enter any 2 values to calculate the missing variable (assumes a constant-chord/rectangular planform where area = chord × span).

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Wing Planform (Reference) Area Formula (Constant Chord)

The following formula is used to approximate the planform (reference) area of a constant-chord (rectangular) wing made from an airfoil section extruded along the span. This is a projected area (often denoted S in aerodynamics), not the wetted surface area of the wing.

A = c \cdot s

Variables:

  • A is the planform (reference) area of the wing (projected area)
  • c is the chord length (assumed constant along the span)
  • s is the span (tip-to-tip). If you use semi-span instead, the formula gives the half-wing area.

To approximate planform (reference) area for a constant-chord wing, multiply the chord length by the span. For non-rectangular planforms, area generally uses an average/mean chord rather than a single chord length.

What is an Airfoil?

An airfoil is a 2D cross-sectional shape designed to generate lift when air flows over it. Airfoils are used as the cross sections of aircraft wings, propeller blades, and other aerodynamic surfaces. The chord length is the straight-line distance between the leading and trailing edges of an airfoil. The span is a wing dimension (distance from one wingtip to the other), not a property of an airfoil by itself.

How to Calculate Wing Planform (Reference) Area?

The following steps outline how to calculate the planform (reference) area of a constant-chord wing.

  1. First, determine the chord length (c) (assumed constant).
  2. Next, determine the span (s) (tip-to-tip).
  3. Finally, calculate the planform (reference) area using the formula A = c * s.
  4. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Chord Length (c) = 5 units

Span (s) = 10 units