Topsoil Calculator
Enter the area and depth to find how many cubic yards of topsoil, fill dirt or compost to order — or how many bags to pick up.
Enter the size of the area and the depth.
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How to use the topsoil calculator
- Measure the area you're covering. For an irregular yard, break it into rectangles and triangles, or measure the square footage from a site plan.
- Enter the depth you want to add. It's the finished depth after the soil settles; the extra percentage covers the difference.
- Choose the material. The density converts yards to tons, since some suppliers sell soil by weight. Moist soil is noticeably heavier than dry soil, so ask your supplier for their figure.
How to calculate topsoil
Worked example: topsoil for a new 30 × 40 ft lawn, 4 inches deep
- Area: 30 × 40 = 1,200 sq ft
- Volume: 1,200 × 4 ÷ 12 = 400 ft³ = 14.8 yd³
- Plus 10% for settling: 16.3 cubic yards — around 16 to 21 tons depending on how moist the soil is.
Worked example: top-dressing 1,000 sq ft of lawn ¼ inch deep
- Volume: 1,000 × 0.25 ÷ 12 = 20.8 ft³ = 0.77 yd³
- That's 28 bags of 0.75 cu ft or less than a cubic yard in bulk.
How much does a yard of topsoil weigh?
Soil weight depends mostly on water content, and also on how much sand, clay and organic matter it contains. As a rough guide, a cubic yard of dry screened topsoil weighs about a ton and moist topsoil 1.3 tons or more. Compost is much lighter — roughly half a ton per yard. That's why a volume (cubic yards) is the safest way to order, and weight is best used to check your truck or trailer's payload.
How much area does a yard of topsoil cover?
| Depth | 1 cubic yard covers | One 0.75 cu ft bag covers | One 1 cu ft bag covers |
|---|---|---|---|
| ½ in | 648 sq ft | 18 sq ft | 24 sq ft |
| 1 in | 324 sq ft | 9 sq ft | 12 sq ft |
| 2 in | 162 sq ft | 4.5 sq ft | 6 sq ft |
| 4 in | 81 sq ft | 2.25 sq ft | 3 sq ft |
| 6 in | 54 sq ft | 1.5 sq ft | 2 sq ft |
How deep should topsoil be?
- New lawns from seed or sod: 4 to 6 inches of good topsoil over loosened subsoil gives roots room to establish.
- Leveling low spots: fill in thin layers of an inch or two, water to settle, and repeat. Filling a deep dip in one go leaves a soft spot that sinks later.
- Top-dressing an existing lawn: spread a thin layer — about ¼ to ½ inch — and rake it in so the grass isn't smothered.
- Garden beds: 6 to 12 inches of loose, fertile soil for most vegetables and flowers. Mix compost into the top layer rather than using pure compost.
Topsoil, fill dirt or garden soil? Fill dirt is subsoil with little organic matter — cheap and good for raising grade under a lawn or patio. Topsoil is the fertile top layer, screened to remove rocks and roots. Garden soil or "planting mix" is topsoil blended with compost for beds.
Frequently asked questions
How many bags of topsoil are in a yard?
36 bags of 0.75 cubic feet, 27 bags of 1 cubic foot, or 18 bags of 1.5 cubic feet.
How much topsoil do I need for 1,000 square feet?
At 4 inches deep, about 12.3 cubic yards before any allowance for settling. At 1 inch deep, about 3.1 cubic yards.
Should I order extra topsoil?
Yes, around 10%. Delivered soil is loose and settles once it's raked, rolled and watered, so the layer ends up thinner than it looked on delivery day.
Can I put new topsoil directly on top of grass?
A thin top-dressing, yes. For more than about an inch, remove or kill the existing turf first, loosen the ground underneath, and then spread the new soil.
Sources
Soil weights are typical planning values and change with moisture and composition — confirm with your supplier. How we calculate.