To find out how many cubic feet of soil you need for your yard or garden, all you need are a few measurements and some simple math. If you have a very large yard, or you need to calculate cubic feet for more than one project, you might find that standard-size measuring tapes are inconvenient because they are too short. Invest in a measuring wheel or an outdoor laser measuring tool, both of which are available at home-improvement stores. They will give you accurate results quickly.
Use a measuring tape to determine the length of the location where you will be placing the soil. Note the measurement in feet.
Measure the width in feet.
Determine the necessary depth of the soil in feet. If you plan to fill a raised garden bed, measure the height of the garden's border. If you're laying the soil in a yard, decide how deep you want it. If the measurement is less than 1 foot, divide the number of inches by 12 to convert it to feet. For example, 3 inches divided by 12 = 0.25 feet.
Multiply the width by the length by the depth to find the number of cubic feet of soil you need. For example, if the length is 10 feet, the width is 10 feet, and the depth is 0.25 feet, the result is 25 cubic feet (10 x 10 x 0.25 = 25)