Topsoil Calculator
Enter your area dimensions and desired topsoil depth to calculate cubic feet, cubic yards, tons, and number of bags needed. Includes an adjustable waste factor for settling and uneven terrain.
What is Topsoil?
A topsoil calculator estimates the volume and weight of topsoil required to cover a given area at a specified depth. Topsoil is the uppermost layer of soil, typically the top 2 to 8 inches, rich in organic matter and nutrients that support plant growth. Whether you are establishing a new lawn, building raised garden beds, or grading a yard, knowing the precise amount prevents costly over-ordering and return trips to the supplier. Topsoil is sold by the cubic yard for bulk delivery or in bags (typically 1 cubic foot per bag) for smaller projects. One cubic yard equals 27 cubic feet and covers approximately 81 square feet at 4 inches deep. Bulk delivery is significantly more economical for anything over 3 to 5 cubic yards, while bags offer convenience for small garden patches and planters. Weight matters for delivery logistics and cost estimation. Topsoil weighs approximately 1.1 tons (2,200 pounds) per cubic yard when moderately dry. Wet topsoil can weigh 1.3 to 1.5 tons per cubic yard, which affects truck load limits. Most dump trucks carry 10 to 14 cubic yards, so large projects may require multiple loads. The waste factor accounts for settling, uneven subgrade, and minor spillage during spreading. A 5 percent waste factor is standard for flat, prepared areas. Increase to 10 to 15 percent for sloped areas, areas with ruts or depressions, or when filling around landscaping features. Topsoil settles approximately 10 to 15 percent over the first year as it compacts naturally, so slight over-ordering is preferable to coming up short. For lawn establishment, the recommended topsoil depth is 4 to 6 inches to provide adequate root zone for grass. Garden beds typically need 6 to 12 inches depending on the plants. Light top-dressing for existing lawns requires only 0.25 to 0.5 inches spread evenly and raked into the existing turf.
How to Calculate
- Measure the length of your area in feet
- Measure the width of your area in feet
- Determine the desired topsoil depth in inches (4 inches is standard for lawns)
- Set the waste factor (5% is standard for level ground, increase for slopes)
- Review the results in cubic feet, cubic yards, tons, and bags
- Choose bulk delivery for orders over 3 cubic yards, bags for smaller projects
Formula
Volume (cubic feet) = Length (ft) x Width (ft) x Depth (in) / 12 Volume with waste = Volume x (1 + Waste Factor / 100) Cubic Yards = Cubic Feet / 27 Tons = Cubic Yards x 1.1 (standard topsoil density) Bags (1 cu ft) = ceiling of Cubic Feet with waste The 1.1 tons-per-cubic-yard conversion factor represents moderately dry, screened topsoil. Wet or clay-heavy soil can weigh up to 1.5 tons per cubic yard.
Example Calculation
A 20 ft x 10 ft area at 4 inches deep with 5% waste: Raw Volume = 20 x 10 x (4 / 12) = 66.67 cubic feet With 5% Waste = 66.67 x 1.05 = 70 cubic feet Cubic Yards = 70 / 27 = 2.59 cubic yards Tons = 2.59 x 1.1 = 2.85 tons Bags = ceil(70) = 70 bags (1 cu ft bags) For this project, ordering 3 cubic yards of bulk topsoil would cover the area with a comfortable margin.
Frequently Asked Questions
How much does a cubic yard of topsoil weigh?
A cubic yard of dry to moderately moist topsoil weighs approximately 1.1 tons (2,200 pounds). Wet topsoil can weigh 1.3 to 1.5 tons per cubic yard. Clay-heavy soil is heavier than sandy or loamy topsoil. Always confirm weight with your supplier when planning delivery, as truck load limits apply.
How deep should topsoil be for a new lawn?
For a new lawn, apply 4 to 6 inches of topsoil over prepared subgrade. This provides adequate root zone for most grass species. If your existing soil is hard clay or very sandy, 6 inches is recommended. For overseeding or top-dressing an existing lawn, 0.25 to 0.5 inches is sufficient.
What is the difference between topsoil and garden soil?
Topsoil is natural soil screened to remove rocks and debris, with varying organic content. Garden soil (or garden mix) is topsoil blended with compost, peat, or other amendments to create an enriched growing medium. Garden soil costs more but provides better nutrients for flower beds and vegetable gardens. Use plain topsoil for grading and lawn establishment.
How much does topsoil settle after installation?
Topsoil settles 10 to 15 percent over the first year as it compacts from watering, foot traffic, and natural gravity. To achieve a finished depth of 4 inches, apply approximately 4.5 inches initially. The waste factor in this calculator partially accounts for settling.
Should I buy topsoil in bags or bulk?
Bags (typically 1 cubic foot each) are convenient for small projects under 1 cubic yard (27 bags). Bulk delivery by the cubic yard is far more economical for larger areas — bulk topsoil costs $20-50 per cubic yard delivered, while bagged topsoil runs $3-7 per cubic foot, or $80-190 per cubic yard equivalent. The crossover point is usually around 2-3 cubic yards.
Can I use fill dirt instead of topsoil?
Fill dirt is subsoil used for grading and structural fill — it lacks the organic matter and nutrients needed for plant growth. Never use fill dirt as the top layer for lawns or gardens. You can use fill dirt to build up low areas, then cap with 4-6 inches of topsoil for the planting layer.