How it works
topsoil volume = area (sq ft) × depth (ft)
The calculator multiplies length by width for the area, converts the depth to feet, and multiplies to get cubic feet; cubic yards are that figure divided by 27. The weight estimate uses a representative moist mineral-soil bulk density of about 92 pounds per cubic foot — the figure implied by the classic soil-science benchmark that the top six inches of an acre of typical mineral soil (an "acre furrow slice") weighs roughly two million pounds. That works out to roughly 2,500 pounds, about 1.2 US tons, per cubic yard. Real topsoil weight swings widely with moisture and compaction — saturated or clay-heavy soil is much heavier, dry sandy soil lighter — so treat the tonnage as a planning figure, not a delivery ticket. Bulk topsoil delivered by the cubic yard is almost always cheaper than bags once you need a yard or more.
Sources
- NC State Extension — Soils and Plant Nutrients The top 6 inches of an acre of typical mineral soil weighs about 2,000,000 lb; over 43,560 ft² that is ≈ 92 lb per cubic foot (≈ 1.2 tons per cubic yard).
- Volume conversions (exact by definition) 1 cubic yard = 27 cubic feet; 1 cubic foot = 28.316846592 litres; 1 US ton = 2,000 lb.
FAQ
How much topsoil do I need?
Multiply the area by the depth. Covering 100 square feet with 4 inches of topsoil takes about 33 cubic feet, or 1.2 cubic yards. Covering 1,000 square feet 4 inches deep takes about 12.3 cubic yards. Enter your own area and depth above for an exact figure.
How much does a cubic yard of topsoil weigh?
Roughly 2,500 pounds — about 1.2 US tons — for typical moist soil, based on a bulk density near 92 pounds per cubic foot. It varies a lot: wet or clay-rich topsoil can top 3,000 pounds a yard, while dry sandy soil is lighter. Check your delivery vehicle or trailer rating before hauling.
How deep should topsoil be for a new lawn?
For a healthy new lawn, aim to establish about 4 to 6 inches of quality topsoil so grass roots have room to develop. For simply leveling minor dips, a thinner layer is fine. Deeper beds for vegetables or shrubs may want more; the depth field lets you set whatever the job needs.
Should I buy topsoil in bags or in bulk?
For a small patch, bags are convenient. But a cubic yard is 27 cubic feet — about 27 one-cubic-foot bags — so any job needing a yard or more is usually far cheaper as a bulk delivery. The calculator shows both the cubic-yard figure and the bag count so you can compare.
Is topsoil the same as garden soil or fill dirt?
Not quite. Topsoil is the upper, more fertile layer of soil and is what this calculator is scoped to — for lawns, beds and leveling. Garden soil is topsoil blended with compost and amendments for planting, while fill dirt is subsoil for structural filling and is not meant for growing.
Can I plant directly in pure topsoil?
You can, but most plants do better in topsoil improved with organic matter. Mixing a few inches of compost into the topsoil raises fertility and improves structure and drainage. Use the compost calculator linked above to work out how much to blend in.
Volumes and weights are estimates. Topsoil density and quality vary with moisture, texture and screening, and loose soil settles. This tool is for garden and lawn topsoil, not construction fill or aggregate. General gardening guidance, not professional advice.