If your wing is not rectangular, the formula cited in post #3 doesn't really apply for it assumes a rectangular wing (i.e. wingspan X chord). The correct formula for wing loading is weight/wing area. If you know the actual wing area, you should use this. For example, if you had a wing with an aft swept leading edge, tapering to the tip, etc., then the formula from #3 wouldn't give the correct result. Use the wing area if you can determine it.