How to figure box size
To figure out how big a box is measure the
Height, Width, and
Depth of the box (in inches) then HxWxD / 1728 will give you the cubic ft. of the box.
Usually you will be concerned with the airspace inside the box so be sure to get the
inside measurements and not the outside measurements for your calculations.
How to figure angles
To calculate a truckbox or one with a simple angle, measure
Height, Width, Top depth and Bottom depth. and use the formula (HxWx(TD+BD)/1728)/2 to
convert it to cubic Ft.
For more than one angle you will have to measure and calculate
sections and then add the sections together for your total.