Topsoil Calculator
Enter the length, width, and depth of your area to find how many cubic yards, 40 lb bags, and tons of topsoil you need. Screened topsoil weighs about 1.1 tons per cubic yard.
How to calculate topsoil
Multiply length × width × depth in feet to get cubic feet, then divide by 27 for cubic yards (how bulk topsoil is sold). A 40 lb bag holds about 0.75 ft³, so divide cubic feet by 0.75 for the bag count. Screened topsoil weighs roughly 1.1 short tons per cubic yard, so multiply the cubic yards by 1.1 for tonnage. Depth is usually entered in inches, so divide it by 12 to get feet. For a new garden bed, 6–12 inches is typical; for top-dressing a lawn, 0.25–0.5 inch is plenty.
Cubic yards = (L ft × W ft × Depth ft) ÷ 27 · Bags = ft³ ÷ 0.75 · Tons = yd³ × 1.1
Worked example
A 20 ft × 10 ft garden bed filled 3 inches deep with topsoil.
- Depth = 3 in ÷ 12 = 0.25 ft
- Volume = 20 × 10 × 0.25 = 50 ft³
- Cubic yards = 50 ÷ 27 = 1.85 yd³
- Bags = 50 ÷ 0.75 = 67 bags (or 1.85 yd³ ≈ 2.04 tons in bulk)
Result: 1.85 cubic yards (about 67 bags, or roughly 2 tons)
Frequently asked questions
How much topsoil do I need?
Multiply length × width × depth in feet to get cubic feet, then divide by 27 for cubic yards. A 20 × 10 ft bed at 3 inches deep needs about 1.85 yd³, which is roughly 67 forty-pound bags or 2 tons. Buying in bulk by the cubic yard is far cheaper than bags once you pass about half a yard.
How much does a cubic yard of topsoil weigh?
Screened, slightly moist topsoil weighs roughly 2,000 to 2,700 pounds per cubic yard (about 1 to 1.35 short tons). This calculator uses 1.1 tons (2,200 lb) as a midpoint. Wet soil and soil with a lot of clay weigh more; dry, sandy mixes weigh less.
How many bags of topsoil are in a cubic yard?
A 40 lb bag holds about 0.75 cubic feet, and a cubic yard is 27 cubic feet, so a cubic yard equals roughly 36 bags. That is why bulk delivery is usually cheaper than bags for anything more than a small bed or a few containers.
How deep should topsoil be?
For a new garden or raised bed, add 6 to 12 inches so roots have room. To level or improve an existing lawn, top-dress with just 0.25 to 0.5 inch and rake it in. For laying new sod, 4 to 6 inches of quality topsoil over the subsoil is a good base.
Should I order extra topsoil?
Yes, add about 10% for settling and uneven ground. Freshly delivered topsoil is fluffy and compacts once watered and walked on, so the finished depth is a little less than the loose volume you spread.