If a plane weighs 16.5 pounds--all you do is multiply that by 16ounces.

16.5 x 16 = 264 -- weight of plane in ounces

To convert square inches of wing area into square feet, simply divide the square inches by 144. There is 144 square inches in a square foot. 12 x 12 = 144

So, if the plane has 1492 square inches. all you do is divide that by 144.

1492 / 144 = 10.3611111111 square feet. Round to 10.36

Now take your total ounces ( 264 ) and dived it by the square feet ( 10.36 )

264 / 10.36 = 25.492625 In my world, that rounds to 25.5 ounces/square foot wingloading.

But, it's not always that simple. Some manufacturers/distributors only give you the actual square inches of the wing panels and NOT the area of the fuse in between the wings. That area DOES count in the equation. It's flying the plane.

So, if your only calculating wing panels--your wingloading will seam kinda high. Figure the root of most 28% planes is about 20--21" cord. Now figure the width of the fuse where the wings are. Usually in the neighborhood of about 8--10" wide.

20" cord X 10" width = 200.

That yields another 200 square inches of wing area. That will have a drastic effect on your wingloading numbers.

We got 25.5 ounces/foot wingloading on the example above. Now lets take out 200 square inches and do the math again.

1292 square inches / 144 = 8.972 square feet of wing

The plane weighs the same, so take your plane weight in ounces ( 264 ) and divide it by the square feet ( 8.972 )

264 / 8.972 = 29.42487 Round to 29.4 ounces/square feet wingloading.

Thats a difference of about 4oz per square foot on the wingloading. And that was simply by ommitting the area in the fuse between the wings.

Be careful how you calculate.

I have no idea how to calculate metric. [sm=spinnyeyes.gif]