How do you calculate wing loading? Is there a excel formula?

From : Don Stackhouse

Wing loading is nothing more than weight divided by wing area. The typical units in the English system are ounces per square foot. Since the plans usually list area in square inches (and there are 144 square inches in a square foot), the formula becomes:

W.L. (in oz./sq.ft.) = (144 x weight in ounces) / (area in sq. in.)

In metric you usually see grams per square decimeter. Divide the weight in grams by the wing area in decimeters.

To convert between the two systems of units:

A. Multiply ounces per square foot by 3.052 to get grams per square decimeter.

B. Multiply grams per sq. decimeter by 0.3277 to get ounces per square foot.

Be careful not to attach too much importance to wing area. It is a good general guideline for estimating the low-speed characteristics of a model, but factors like airfoil characteristics, planform and aspect ratio can cause HUGE variations in behavior. It's very possible to have a model with a higher wing loading that is capable of flying efficiently and controllably at a lower speed than another model with a low wing loading. "Rules of thumb" such as wing loading are a good starting point for evaluating a design, but be careful not to rely on them too much.

Don Stackhouse
DJ Aerotech