Okay guys.

I am impressed with all the formulas and explanations and reasonings regarding this forums' topic.

Consider this: Tractor trailer pulls into loading dock. Truckers do not get paid for sitting around but they do get paid handsomely for driving on the highways. The forklift operator who may just have a high school education with mathematics being the poorest subject of all, has to make the determination as to whether he can safely unload the oddball pallets. Honestly, and definitely no offense to John or anyone who has submitted an explanation, of which I understand all, will this character be able to work out this rule of thumb as submitted by John, or any of the other posters? If you explain that 1"=100lbs, can they all tell you what 5"=? Don't laugh. Its true.
So, what has to be determined is, what is the easiest, and safest means to determine this rule of thumb rule? In my opinion, although not necessarily accurate, is the 1"=100lbs. Anything more complex than that is going to mess with most of these operators' minds. And getting fed up with difficult equations will result in these operators NOT working anything out, and just acquiring the pallets any which way they please, which will definitely result in more errors and incidents.

K.I.S.S.