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Dirt calculator
Fill dirt, topsoil or soil for a raised bed. Enter the space, get cubic yards for a bulk order, bag counts for a small one, and the weight before you commit a pickup truck to it.
Quick answer
Length in feet times width in feet times depth in feet, divided by 27, gives cubic yards. A 10 ft by 10 ft area at 6 inches deep needs 1.85 cubic yards, about 2.1 yards once settling is covered. That is 56 bags at 1 cu ft, which is why bulk delivery wins at this size. The calculator below runs your exact numbers and updates as you type.
How to calculate cubic yards of dirt
Dirt is sold by volume, so the job is converting your space into cubic yards.
Cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27
Depth is the step people miss. Six inches is 0.5 ft. Enter depth in inches in the tool and it converts for you. The settle allowance then covers the fact that loose delivered dirt compacts once it is spread, rained on and walked over.
Constants used on this page
| Constant | Value used | Where it comes from |
|---|---|---|
| Cubic feet per cubic yard | 27 | Definition. 3 ft × 3 ft × 3 ft. |
| Weight of fill dirt | About 2,100 lb per cubic yard | Midpoint of the usual 2,000 to 2,200 lb range for dry fill dirt. Wet material weighs more. |
| Bag sizes | 1 cu ft and 1.5 cu ft | The two bag sizes most US hardware stores stock for topsoil and garden soil. |
| Settle allowance | 10% default | Planning rule of thumb: 10% hand placed, 15 to 25% machine compacted fill. |
Worked example
A 10 ft by 10 ft garden area at 6 inches deep holds 10 × 10 × 0.5 = 50 cubic feet, which is 1.85 cubic yards. With the 10% settle allowance the order is about 2.1 cubic yards, so a 2 yard bulk drop plus a couple of bags, or 3 yards if your supplier only runs whole yards. In bags that same job is 56 bags at 1 cubic foot, which is why bulk wins past small patches. Weight: roughly 4,400 lb delivered, far past one pickup load.
Dirt calculator FAQs
How many cubic yards of dirt do I need?
Multiply length in feet by width in feet by depth in feet, then divide by 27. A 10 ft by 10 ft area at 6 inches deep is 10 × 10 × 0.5 ÷ 27, which is 1.85 cubic yards. Order about 2 yards with a small settle allowance.
How many bags of dirt are in a cubic yard?
A cubic yard is 27 cubic feet. That is 27 bags at 1 cubic foot each, or 18 bags at 1.5 cubic feet each. Past about 2 cubic yards, bulk delivery is almost always cheaper than bags.
How much does a cubic yard of dirt weigh?
Dry fill dirt runs about 2,000 to 2,200 pounds per cubic yard. Wet dirt can pass 2,500 pounds. We use 2,100 pounds as a planning midpoint, which matters if you are hauling it yourself in a pickup.
Should I add extra dirt for settling?
Yes. Loose dirt compacts after rain and foot traffic. Add 10 percent for a garden bed you will top up by hand, and 15 to 25 percent for fill that gets compacted in layers with equipment.
What depth of topsoil do I need for a new lawn?
Four to six inches of topsoil under sod or seed is the usual target. Grass roots live in that top layer, and going thinner shows up as a lawn that dries out first every summer.