Topsoil is ordered in Cubic Yards. the formula to calculate how much you need is as following: LENGTH X WIDTH X HEIGHT will produce the Cubic FEET needed, then divide that number by 27 to get the number of Cubic YARDS that you need to order. *(Keep all measurements in Feet. If in inches, please note that 3″ = .25 feet, 4′ = .334 feet, 6″ = .50 feet)
Example: Bob needs to fill an area with topsoil, 100′ long, 50′ wide, and .5 feet deep (6 inches). 100 X 50 X .5 = 2500
Divide 2500 by 27, to get 92.59 Cubic yards that Bob needs to order.
Divide his 92.59 by 18, which means he has to order 5.14 truck loads.
Bob should order 6 truck loads to compensate for compaction over time.