Topsoil calculator
Covering a 40 × 25 ft lawn area with 4 in of topsoil takes 12.35 cubic yards, which weighs about 14.81 tons. Enter your own area and depth.
The extension formula
Extension services give a simple rule: area in square feet × depth in inches ÷ 324 = cubic yards. It works because a cubic yard spread 1 in deep covers 324 sq ft. The calculator does the same arithmetic and also shows bags and weight.
Area: 40 ft × 25 ft = 1,000 sq ft
1,000 sq ft × 4 in = 333.33 cu ft ÷ 27 = 12.35 cu yd
12.35 cu yd × 2,400 lb per loose cu yd ÷ 2,000 = 14.81 tons
How deep for a lawn
Penn State Extension says a minimum of 4 to 6 in of good topsoil, measured after it has been firmed or has settled, is needed to establish good turf. Loose topsoil settles after it is spread and watered, so order for the settled depth you want plus a little more, and firm it before seeding or laying sod. If you are adding topsoil over existing soil, Penn State also suggests working the bottom of the new layer into the soil below so water and roots move between them.
| Area | 2 in deep | 4 in deep | 6 in deep |
|---|---|---|---|
| 100 sq ft | 0.62 | 1.23 | 1.85 |
| 250 sq ft | 1.54 | 3.09 | 4.63 |
| 500 sq ft | 3.09 | 6.17 | 9.26 |
| 1,000 sq ft | 6.17 | 12.35 | 18.52 |
| 2,000 sq ft | 12.35 | 24.69 | 37.04 |
| 5,000 sq ft | 30.86 | 61.73 | 92.59 |
Bags or bulk
Bagged topsoil is sold by volume. For a raised bed 8 × 4 ft filled 12 in deep, you need 1.19 cubic yards: 22 bags of 1.5 cu ft. Past a cubic yard or two, a bulk delivery usually costs less per yard than bags.
| Bag size | Bags per cu yd | Rounded up |
|---|---|---|
| 0.75 cu ft | 36 | 36 |
| 1 cu ft | 27 | 27 |
| 1.5 cu ft | 18 | 18 |
| 2 cu ft | 13.5 | 14 |
What topsoil weighs
The calculator uses 2,400 lb (1.20 tons) per loose cubic yard, from the EPA's figure of 2,392 lb for loose sandy loam. Caltrans lists dry, loose clay soil at 2,160 lb per yard. Damp soil weighs more, which matters if you are hauling it in a pickup or trailer.
Sources
- Lawn Establishment, Penn State Extension, updated September 2025. A minimum of 4 to 6 in (settled depth) of good topsoil to establish a lawn.
- How Much Compost, Soil or Mulch Do I Need to Purchase?, Texas AgriLife Extension Service, Travis County, February 2010. Square feet times depth in inches, divided by 324, gives cubic yards.
- Standard Volume-to-Weight Conversion Factors, U.S. Environmental Protection Agency, March 2016. Loose weights of gravel, rock, sand, sandy loam soil and shredded wood chips.
- Maintenance Manual Volume 1, Appendix: Useful Information, California Department of Transportation, July 2014. Loose weights of crushed gravel, limestone, granite, screenings, sand and soil; 111 lb of asphalt mix per square yard per inch; 2.0 tons per compacted cubic yard of base.