Topsoil & Fill Dirt Calculator

How to use

1. Enter your area as a rectangle, circle, triangle, or type in a square footage you already know.
2. Pick a project preset: new lawn, top dressing, garden bed, or a thin leveling pass over a lawn. Each fills in a sourced typical depth. For a deeper hole or dip, type its depth instead.
3. Choose topsoil, fill dirt or garden soil mix from the material list; they have different typical weights per cubic yard.
4. Adjust the depth if your project needs more or less than the preset suggests.
5. Read the result: cubic yards, tons, bag count and an order line rounded to what a supplier or store actually sells.

How it works

The volume calculation follows the same math as the other tools on this site: length times width times depth for a rectangle, or the matching formula for a circle or triangle, with depth converted from inches to feet before multiplying, then the cubic-foot total divided by 27 to get cubic yards. Weight comes from multiplying cubic yards by the typical tons-per-cubic-yard figure for whichever soil you picked, along with its minimum and maximum. Soil weight swings more than most landscaping materials: wet topsoil can weigh considerably more than the same soil dry and screened, and garden soil mix blended with compost is noticeably lighter and fluffier than plain topsoil or fill dirt.

Fill dirt and topsoil aren’t interchangeable even though both are sold by the cubic yard. Topsoil is meant to support plant growth and is usually screened to remove rocks and debris, while fill dirt is subsoil used to raise or level ground and isn’t meant to grow anything in. Garden soil mix sits apart from both: it’s topsoil or a similar base blended with compost or other organic matter specifically for planting beds.

Two adjustments apply before you order: an extra percentage for settling that varies by soil type, since loose soil compacts once it’s spread, rained on and walked on, and rounding, since the order line rounds volume up to the next half cubic yard, weight up to the next half ton, and bag counts up to a whole bag. Bags matter more here than for some other materials. Topsoil and garden soil mix are commonly sold in 0.75, 1 and 1.5 cubic foot bags as well as in bulk, and the calculator shows a bag count for each of those sizes. Fill dirt is bulk only; it isn’t sold in bags.

Limits: this assumes a flat area at one constant depth. A yard with high and low spots needs more soil than the flat math shows for leveling, so add a separate area for the low spot instead of applying one depth across the whole space. For a real dip, expect to repeat a thin leveling layer over several weeks rather than filling it in one pass, since a single leveling application is meant to stay shallow. Treat every result as a planning estimate; soil moisture on delivery day will shift the actual weight your supplier scales out.

Topsoil depth guide

These depths come from university extension guidance on lawns and raised beds, plus lawn-care sources on top dressing and leveling.

Worked example

1. Area: 32 ft × 18.5 ft = 592 sq ft
2. Depth: 4 in ÷ 12 = 0.333 ft
3. Volume: 592 sq ft × 0.333 ft = 197.33 cu ft
4. Extra for settling: 197.33 cu ft × 1.10 = 217.07 cu ft
5. Cubic yards: 217.07 ÷ 27 = 8.04 cu yd (6.15 m³)
6. Weight: 8.04 cu yd × 1.1 tons per cu yd = 8.8 tons (8.0 tonnes)
7. Order: round up to 8.5 cubic yards, or 290 bags of 0.75 cu ft

Questions people ask

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