What is the proper way to measure wing area?

I can easily determine how many Sq. Inches or Sq. Feet in a wing half using Autocad. Is is but a punch of the button.

However, I have one old book which states to ignore the area which passes through a fuselage, and a different one which states the opposite.

In figuring wing area for loading calculations, should I use the total wing,

subtract out the area within the fuselage and engine nacelles on a multi,

should I use some formulae for it is is a high wing, a low wing, a parasol, or a mid-wing?

Should I use the area "as projected" due to dihedral, or as flat?

On large sized models adding in or subtracting out the areas is a significant number.


Wm.