When planning landscaping or gardening projects requiring large amounts of soil, you will encounter the term “yard” when purchasing from a bulk supplier. This term is a specific unit of measurement that buyers must understand to ensure they order the correct quantity. Misunderstanding this terminology can lead to cost overruns, delays, or multiple trips to acquire more soil. Buying in bulk by the yard is typically the most cost-effective solution for significant projects, but only if you accurately translate your project’s dimensions into the supplier’s volume unit. Calculating your needs correctly prevents both the waste of excess material and the frustration of running short halfway through a job.
What Constitutes Quality Topsoil
Topsoil is the uppermost layer of earth, typically ranging from 2 to 8 inches deep, where the highest concentration of organic matter and microbial life exists. Quality topsoil is ideally composed of approximately 45% mineral particles, 25% water, 25% air, and 5% organic matter. This organic material, known as humus, is derived from decaying plant and animal matter and provides the essential nutrients and structure for healthy plant growth.
The mineral component consists of a blend of sand, silt, and clay particles, with a balanced ratio often referred to as loam. A loamy texture is generally considered superior because it allows for good drainage while still retaining sufficient moisture and nutrients. When purchasing topsoil in bulk, you will often find it categorized as “screened,” which indicates it has been sifted through a mesh to remove large rocks, roots, and debris. Vendors may also offer blended mixes, which are topsoil enriched with additional compost or sand to optimize it for specific uses like vegetable gardens or laying sod.
The Meaning of a Cubic Yard
When a supplier refers to a “yard” of topsoil, they mean a cubic yard, which is the standard unit of volume. A cubic yard is a three-dimensional measurement equivalent to a cube 3 feet long, 3 feet wide, and 3 feet high. This volume totals exactly 27 cubic feet of material. Topsoil is sold by volume, not by weight, due to the highly variable moisture content of the material.
The weight of one cubic yard can fluctuate depending on how wet it is. Dry, loose topsoil may weigh around 1,080 pounds, but if saturated with water, its weight can increase to 2,000 pounds or more. Selling by volume ensures a consistent measure of the space the material will occupy in your project, regardless of moisture level. Therefore, you must always calculate your order in cubic yards.
Relating Volume to Project Coverage
Understanding the coverage rate translates the volume measurement into a practical dimension you can apply to your project area. Coverage depends entirely on the depth you plan to spread the material. The key conversion factor is that one cubic yard contains 27 cubic feet.
If you spread the topsoil to a depth of 1 inch, a single cubic yard will cover an area of approximately 324 square feet. Increasing the depth to 2 inches reduces the area covered by half, covering about 162 square feet. For a substantial depth, such as the 3 inches often recommended for establishing new lawns or garden beds, one cubic yard covers roughly 108 square feet. Many suppliers estimate a yard covers 100 square feet at 3 inches deep, which provides a small margin for settling or uneven application.
Determining How Much Topsoil to Order
The most effective way to determine your topsoil needs is to follow a precise, three-step calculation process based on your project dimensions. First, accurately measure the length and width of the area you intend to cover, recording both values in feet to establish the total square footage. Second, decide on the required depth for your project, which may be 1 to 3 inches for lawn leveling, or 6 to 12 inches for a raised garden bed.
Next, you must convert your desired depth from inches into a fraction of a foot. For example, a depth of 3 inches is 0.25 feet (3 divided by 12). You then multiply your area’s length, width, and converted depth together to find the total volume in cubic feet: Length (ft) × Width (ft) × Depth (ft) = Cubic Feet. Finally, divide this total number of cubic feet by 27 to obtain the number of cubic yards you need to order, since there are 27 cubic feet in one cubic yard. Always consider rounding the final number up to the nearest half or whole yard, as it is common for topsoil to settle slightly after delivery and spreading.