Sue,

I have a confession. I have not kicked back today either. I cleaned my entire barn including four stalls. Bathed three horses, clipped and groomed. Put out hay in the managers in corrals. Mowed entire lawn. Did laundry, cleaned house. mopped floors. answered AW2000 questions, listed some BIN. I won't go on. So I didn't follow my own advice

If your package is over a cubic foot, you should elect the Oversize 1 and include the dimensions in Aw2000.

The 84 inches is for parcel packages not Priority. Priority is dimensional weight. So you take the box size all three dimensions x each other. If the sum is greater than 1728, then divide by 194 and that gives you the dimensional weight you use to determine the shipping cost.

Parcel Post packages are determined to be oversize if the length, plus girth plus height is over 84 inches.

Your 16 x 16 x 12 box is 3072 inches. Divide 3072 by 194 for a total of 15.83. Which must be rounded up to the next pound to 16 lbs. So when calculating shipping you would use the 16 lbs as the weight factor to the zip code of buyer. Does that make any sense at all??

None of the Priority boxes provided by the USPS are over a cubic foot. There is one box but it isn't Priority and its name escapes me at the moment.

Does that help at all or did I completely confuse everything??

Judy/blue