Topsoil Volume Calculator
Topsoil is sold by the cubic yard or by the bag, so to order the right amount you need the volume of the area you are filling. This calculator takes the length, width, and depth of your bed or lawn area and returns the volume in cubic feet and cubic yards, the number of typical bags, and the approximate delivered weight using an editable soil density.
Topsoil volume formula
Depth (ft) = depth (in) / 12
Volume (cubic ft) = length * width * depth (ft)
Volume (cubic yards) = cubic ft / 27
Bags = cubic ft / bag size
Weight = cubic ft * density
There are 27 cubic feet in a cubic yard. Topsoil density varies with moisture and composition, commonly around 70 to 90 lb per cubic foot (roughly 1,900 to 2,400 lb per cubic yard); adjust the density input for your soil.
Worked example
A 20 by 10 foot bed filled 4 inches deep: depth = 4 / 12 = 0.33 ft. Volume = 20 times 10 times 0.33 = 66.67 cubic ft = 2.47 cubic yards. At 0.75 cubic ft per bag that is about 89 bags, or one bulk delivery. At 75 lb per cubic foot the soil weighs about 5,000 lb.
Topsoil ordering notes
- One cubic yard equals 27 cubic feet; bulk topsoil is normally priced by the yard.
- Topsoil density depends on moisture and organic content, commonly 70 to 90 lb per cubic foot.
- Bagged topsoil is usually sold in 0.75 or 1.0 cubic foot bags; check your bag size.
- For new beds, 4 to 6 inches of topsoil is typical; for top-dressing a lawn, much less.
- Order a little extra to allow for settling and uneven ground.
Topsoil Volume Calculator: frequently asked questions
How many cubic yards of topsoil do I need?
Multiply the area length by width by depth (all in feet) to get cubic feet, then divide by 27 to get cubic yards. A 20 by 10 foot bed at 4 inches deep needs about 2.47 cubic yards.
How much does a cubic yard of topsoil weigh?
It depends on moisture and composition, but a cubic yard of topsoil typically weighs between about 1,900 and 2,400 pounds (roughly 70 to 90 pounds per cubic foot). Wet soil weighs more. This calculator uses an editable density.
How deep should topsoil be?
For establishing new garden beds, 4 to 6 inches of topsoil is common. For overseeding or top-dressing an existing lawn, a quarter to half an inch is usually enough. Enter your planned depth to get the volume.
How many bags of topsoil are in a cubic yard?
A cubic yard is 27 cubic feet. With 0.75 cubic foot bags, that is 36 bags per cubic yard; with 1.0 cubic foot bags, 27 bags. Bulk delivery is usually cheaper for large volumes.
Sources and methodology
- Volume geometry (length times width times depth, 27 cubic feet per cubic yard) is a fixed mathematical and unit-conversion fact.
- Topsoil density is a user-editable input because it varies with moisture and composition.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.