Ok, cool got it. So let me make sure that I am getting the rest of the process correct. Now I just times 14x 35.25x 16.5 =8142.75 then divide 8142.75 into 1728 which equals 4.71 and then divide 4.71 by 2 =2.3 cu. ft. . Is that correct. One more thing that I forgot to mention. should I use polyfill? if i do it says on the instructions to only use 50% poly fill now is that having 50% of the cu.ft. filled?It really does not specify to go by what. So should I go by 1lb. per cu. ft.?