Free landscaping calculator
Topsoil Calculator — beds & lawns
For raised beds, leveling low spots, and topdressing. Includes a settling allowance so beds don't end up short.
Includes a 10% settling allowance — fresh soil compacts once it's watered in.
How much soil for a raised garden bed?
Multiply your bed's length × width × depth (in feet) to get cubic feet, then divide by 27 for cubic yards. Because fresh soil settles 10–15% after its first thorough watering, the calculator adds a 10% allowance so your bed doesn't sit an inch low after the first rain.
| Bed size | Soil needed |
|---|---|
| 4 × 4 ft | 0.65 yd³ (about 12 bags) |
| 4 × 8 ft | 1.3 yd³ (about 24 bags) |
| 4 × 12 ft | 2.0 yd³ (about 36 bags) |
| 3 × 6 ft | 0.75 yd³ (about 14 bags) |
Bag counts above use 1.5 cu ft bags. Many gardeners fill the bottom third of deep beds with plain topsoil and save richer, compost-heavy mix for the top layer where roots actually feed.
Topsoil vs. garden soil vs. compost
Topsoil is screened natural soil — good for filling volume, grading, and leveling. Garden soil is topsoil blended with organic matter, meant for planting directly. Compost is pure organic matter, used as an amendment or thin topdressing rather than structural fill. For raised beds, a common mix is roughly 60% topsoil, 30% compost, and 10% aeration material.
Topdressing a lawn
Lawn topdressing uses a thin layer, usually ¼ to ½ inch. Enter your lawn's dimensions with 0.5 as the depth: at half an inch, one cubic yard spreads across roughly 650 square feet.
Frequently asked questions
How much soil do I need for a 4x8 raised bed?
A 4 by 8 foot bed filled 12 inches deep needs about 32 cubic feet of soil, or roughly 1.3 cubic yards once settling is accounted for. That's about 24 bags at 1.5 cubic feet each.
How many bags of soil equal a cubic yard?
A cubic yard is 27 cubic feet: 36 bags at 0.75 cu ft, 27 bags at 1 cu ft, 18 bags at 1.5 cu ft, or 13.5 bags at 2 cu ft.
Why does soil settle after filling?
Fresh screened soil is fluffed with air. Watering collapses those air pockets, so the level drops 10 to 15 percent in the first weeks. Overfill slightly, or plan to top up after the first month.
Is bulk soil cheaper than bagged?
Almost always. Bulk topsoil commonly costs a third to half the per-yard price of bagged soil. Bags win only for small jobs, tight access, or when you need a specific sterilized mix.