Dirt is often measured in yards, specifically cubic yards. This measurement takes into account the depth of the dirt, not just the area. If you want to calculate how many cubic yards of dirt you already have, some measuring and a simple formula will do the trick. This same formula will also help you buy dirt, because the cubic yardage is usually stated on the labels of soil products, as well as on similar items such as mulch and sand. The label measurements help you determine how much to buy to fill in your space.
Measure the length and width of the area where you want to lay dirt, or the area in which the dirt is already present. Use feet as your unit of measurement.
Measure the depth of the dirt that is already present (usually just the good loamy topsoil is measured in a home garden or yard), or decide how deep you want the purchased dirt to be. If you measured in inches, you must convert it to feet. Every inch equals approximately 0.0833 feet.
Multiply the three numbers, using the measurements in feet: length x width x depth.
Divide by 27. The result is the cubic yards of dirt you already have or need to buy to fill in the area.