How many 12 inch x 12 inch x 20 inch boxes would fill a cargo container?

12 inches x 12 inches = 1 square foot.

12 inches = 1 foot

13 inches) x (12 inches) x (16 inches) = 1.44444444 cubic ft. More about calculator.

112

To find this you should put the lengths given in feet so the box would be 1 ft x 3/2 ft x 29/24 ft 87/48 cubic ft = 29/16 cubic ft or 1.825 cubic ft