Topsoil Calculator
Calculate how much topsoil you need in cubic feet and cubic yards, with optional bag counts.
How to use
Enter bed length, width, and depth, set waste if you want a buffer, confirm bag volume from packaging, then calculate.
How the calculation works
Dimensions convert to a rectangular volume in cubic feet and cubic yards. Waste adjusts the volume, then bags use your bag size.
Formula
volume_ft³ = length_ft × width_ft × depth_ft; volume_yd³ = volume_ft³ ÷ 27; adjusted = volume × (1 + waste%/100); bags = ceil(adjusted_ft³ ÷ bag_volume_ft³)
Example calculation
A 20 ft × 10 ft bed at 4 in deep is 66.67 ft³ (about 2.47 yd³) before waste.
Assumptions
Shape
Simple rectangular bed
Material: topsoil · Key: geometry
Approximate irregular beds with average length/width.
Source: Geometric model
Default bag volume (ft³ / bag)
1 ft³ per bag
Material: topsoil · Key: bag_yield
Retail bag sizes vary (often 0.75–1.5 ft³). Confirm packaging.
Source: Planning default — confirm with your product label or supplier quote. Not a lab or manufacturer certification.
Settling
Not fully modeled
Material: topsoil · Key: compaction
Soil can settle after placement; depth is the target you enter.
Source: Model limitation
Practical notes
- Bulk delivery is often better for larger volumes.
- Screened topsoil quality varies — ask what is in the mix.
- Raised beds may need more depth than thin lawn top-dressing.
Limitations
- Does not model slope or irregular bed shapes precisely.
- Bag sizes vary — confirm packaging.
- Planning estimate only.
FAQ
- How deep should topsoil be?
- It depends on the project. Thin top-dressing may be about an inch; new beds often use several inches. Follow planting guidance.
- Yards or bags?
- Small patches are often bagged; larger beds are usually ordered in cubic yards.
Related calculators
Results are planning estimates. See the Calculator Disclaimer.