The cost of a cubic foot of dirt, or soil, is not a fixed price and varies widely depending on the material’s composition, the quantity purchased, and the method of sale. Soil is a complex mixture of minerals, organic matter, water, and air. Its purpose—whether for structural fill or nurturing plant life—directly impacts its commercial value. Most large-scale purchases are calculated in cubic yards, which is a volume equal to 27 cubic feet. Analyzing the components that influence soil quality and delivery logistics is the clearest way to determine the true cost for any landscaping or construction project.
What Determines the Price of Soil?
The cost per cubic foot of soil is affected by whether it is bought in small bags or in large bulk quantities. Purchasing soil in bags from a garden center results in a higher price per unit volume due to the added costs of packaging, handling, and retail markup. A single cubic foot of high-quality, bagged topsoil or planting mix can cost between $3.00 and $6.00.
When purchasing soil in bulk, the price drops because the material is delivered loose in a dump truck, eliminating packaging expenses. Bulk soil is typically sold by the cubic yard, translating to a much lower price per cubic foot. Standard bulk topsoil might range from $10 to $50 per cubic yard, which costs approximately $0.37 to $1.85 per cubic foot.
The type and quality of the soil material are the primary cost factors, with specialty blends commanding a premium. Delivery fees also represent a significant portion of the total cost, often adding $50 to $150 or more depending on the distance from the supplier. For smaller projects, this delivery charge can make bulk purchasing less cost-effective than buying a few bags. Regional market conditions, local availability, and seasonal demand influence the final price of soil materials.
Understanding Different Types of Soil
The wide price range for soil reflects the material’s composition and intended function. Soil is generally categorized into three main types for commercial purposes, each having a distinct price point and use case. The lowest-cost option is fill dirt, which consists mainly of sand, silt, and clay with minimal organic matter or nutrients.
Fill dirt is used for structural purposes, such as raising the elevation of a site, backfilling foundations, or creating stable sub-layers where vegetation growth is not a concern. Because it requires minimal processing and is excavated from lower subsoil layers, it is the least expensive material. This material is dense and provides a solid base for construction projects due to its low organic content, which prevents decomposition and settling.
Topsoil represents a mid-range cost material and is the upper layer of earth containing the organic matter, minerals, and nutrients necessary for plant life. Unscreened topsoil may contain debris like small rocks and roots. Screened topsoil is processed through a mesh to create a finer, uniform texture suitable for lawns and gardens, promoting better root development and water retention.
The highest-cost category includes amended or specialty soils, such as garden soil, potting mixes, and compost-enriched blends. These materials are engineered by mixing topsoil with specific amendments like peat moss, compost, or sand to enhance drainage, aeration, and fertility. The addition of high-value organic components makes these specialty mixes the most expensive, but their superior performance justifies the cost for vegetable gardens or high-end landscaping.
How Much Does a Cubic Foot of Soil Weigh?
While soil is purchased by volume, its weight is a factor for transportation, delivery, and handling logistics. The weight of a single cubic foot of soil is highly variable, depending on the soil type and its moisture content. The average weight range for a cubic foot of common soil materials falls between 60 pounds and 140 pounds.
Dry, loose topsoil, which has a higher concentration of air and organic matter, tends to be on the lighter end of this spectrum, often weighing around 75 to 80 pounds per cubic foot. Conversely, dense materials like wet fill dirt or clay-heavy soil can weigh more, sometimes exceeding 120 pounds per cubic foot. The presence of water increases the density, as a cubic foot of water alone weighs approximately 62.4 pounds.
This weight variability is why bulk materials are sometimes sold by the ton, especially in commercial construction, rather than by volume. For a residential project, understanding the weight ensures a vehicle or trailer can safely manage the load during transport. A standard cubic yard (27 cubic feet) of average soil can weigh anywhere from 1,600 pounds to over 3,000 pounds.
Calculating Volume for Your Project
Determining the amount of soil needed requires calculating the volume of your project area, which must be converted into cubic feet for an accurate order. The basic formula for calculating the volume of a rectangular or square area is Length multiplied by Width multiplied by Depth. This calculation must use the same unit of measurement for all three dimensions.
If depth measurements are in inches, you must first convert that figure into a fraction of a foot before multiplication. For instance, 3 inches converts to 0.25 feet, and 6 inches converts to 0.5 feet. Multiplying the length, width, and converted depth (all in feet) yields the total required volume in cubic feet.
For example, a garden bed measuring 10 feet long by 4 feet wide that requires 6 inches of new soil would be calculated as 10 feet x 4 feet x 0.5 feet, equaling 20 cubic feet of material. Since bulk soil is often sold by the cubic yard (27 cubic feet), you can divide your total cubic feet by 27 to determine the required cubic yards. Common landscaping depths range from 3 inches for topdressing an existing lawn to 8 inches for constructing a new raised garden bed.