A fully loaded concrete truck has a maximum load capacity of 10 cubic yards. Ten cubic yards of concrete covers an area of between 270 and 810 square feet, depending on the thickness of the concrete slab.
Experienced concrete contractors realize the importance of ordering the correct amount of concrete needed to complete a job and take care to get it correct. Because job sites are imperfect, contractors typically order 10 to 15 percent more concrete than needed to account for spillage, uneven ground and form movement. This often leads to extra concrete after a pour is completed, but having more than is needed is preferable to having too little. A shortage wastes time and money, as workers are idle while waiting for the concrete truck to return, and the contractor incurs additional costs.
Concrete companies apply an extra fee to the total invoice amount when a contractor orders less than a full load of concrete. Whenever a concrete truck delivers a load, certain fixed costs are incurred. When the truck is carrying a full load, these costs are covered. When the truck is carrying less than a full load, these cost are not covered, so the additional fee is added to meet the full cost of delivery.