Dump trucks do the heavy hauling for everything from large commercial construction projects to the delivery of materials for a small backyard landscaping job. These trucks come in a variety of sizes and capacities. Choosing the right dump truck for a particular job often means that one needs to know the capacity of the truck as it is expressed in load volume. Follow these steps below to calculate this volume.
Consider the bed of the dump truck as a box or three dimensional rectangle, technically described as a parallelepiped.
Obtain the length of the truck bed in feet. We will call this value "l".
Obtain the width of the truck bed in feet. We will call this value "w".
Obtain the height of the truck bed in feet. We will call this value "h".
Plug the values obtained into the following formula: (see graphic) Volume = l_w_h
Divide the volume you have just calculated in cubic feet by 27. The resulting number is the volume of the dump truck, expressed in the standard for such ratings, cubic yards.
When earthen material is delivered by a dump truck, the load will be crowned, or rounded on top. A common way to estimate the volume of such material is to take the volume as calculated above and add 1/2 cubic yard for crowning.