I have a bunch of usps shipping boxes that i dont need, I got them free from the usps office.. a few years back and ive used most but still have a lot.
Here are the sizes i got:

Priority Mail
11-7/8" x 3-3/8" x 13-5/8"
"8.625" x "5.375" x "1.625"
9.25" x 6.25" x 2"
"12.125" x "13.375" x "2.75"
"12.5" x "15.5" x "3"
7" x 7" x 6"
12.5" x 9.5"

i have a few international, express mail, flat rate boxes also.

Need all gone taking up to much space.. Good for Ebay selling :D