Topsoil Calculator
Calculate how many cubic yards or bags of topsoil you need to fill a garden bed or lawn area.
How to use this tool
- Enter the area dimensions in feet and the desired soil depth in inches.
- The calculator returns cubic feet, cubic yards, and equivalent 40 lb bags.
- Order bulk delivery for areas over 2 cubic yards — it's more economical.
Estimate how much topsoil to order for lawn repairs, raised beds, or landscaping.
Formula
Volume (ft³) = Length (ft) × Width (ft) × Depth (in) ÷ 12
Cubic yards = Volume (ft³) ÷ 27
40 lb bags = ⌈Volume (ft³) ÷ 0.75⌉
How it works
The calculator multiplies the area's length by width by depth (converting inches to feet) to obtain the required volume in cubic feet, then divides by 27 for cubic yards. The bag count assumes a standard 40 lb bag of topsoil covers approximately 0.75 cubic feet; the result is rounded up to the nearest whole bag. Actual coverage per bag varies by product density, so check the manufacturer's label; the bulk cubic yard figure is usually more accurate for large projects.
Worked example
Worked example
- Area: 10 ft × 10 ft, 6 in deep.
- Volume (ft³) = 10 × 10 × (6 ÷ 12) = 10 × 10 × 0.5 = 50 ft³.
- Cubic yards = 50 ÷ 27 ≈ 1.852 yd³.
- Bags (40 lb) = ⌈50 ÷ 0.75⌉ = ⌈66.67⌉ = 67 bags.
Volume = 50 ft³; cubic yards ≈ 1.852 yd³; 40 lb bags needed = 67.
Key terms
- Topsoil
- The uppermost layer of soil, rich in organic matter and nutrients; used to establish or improve garden beds and lawns.
- Cubic yard (yd³)
- Equal to 27 cubic feet; the standard unit for bulk topsoil delivery.
- 40 lb bag coverage
- A standard 40 lb bag of topsoil typically covers about 0.75 cubic feet, though this varies by product density.
- Soil depth
- Recommended topsoil depth: 4–6 in for new lawns, 8–12 in for vegetable gardens.
- Amended soil
- Topsoil mixed with compost or other additives to improve drainage, nutrient content, or texture.
Frequently asked questions
- How much topsoil do I need?
- Multiply length × width (ft²) by depth in feet (inches ÷ 12). Divide by 27 for cubic yards. A 40 lb bag holds roughly 0.75 cubic feet.
- How deep should topsoil be for a lawn?
- A minimum of 4–6 inches of good topsoil is recommended for healthy grass. For raised vegetable beds, aim for 12 inches or more.