How much clay do I need?
Clay is used to seal ponds, build berms, and make a firm, low permeability layer in landscape and drainage work.
Enter the length, width, and depth of your area above. The calculator shows cubic yards, cubic feet, an estimated weight in tons, and the number of bags if you buy bagged clay. Add a price per cubic yard and it also estimates the cost.
Cubic yard calculator for clay
This cubic yard calculator for clay works for any shape. Pick rectangle for most beds and slabs, circle for round areas, or trench for narrow runs. Open the price estimator under the calculator to add your supplier price, delivery fee, and tax. For a full cost breakdown, see the cubic yard price estimator.
Clay weight and bags per cubic yard
A planning value for clay is 2,700 pounds per cubic yard, which is 1.35 US tons. Moisture, particle size, and compaction move that number, so treat it as a starting point.
| Measure | Value |
|---|---|
| Pounds per cubic yard | 2,700 |
| US tons per cubic yard | 1.35 |
| Kilograms per cubic yard | 1,225 |
| Cubic yards per US ton | 0.74 |
| Cubic feet per US ton | 20.00 |
How far does a cubic yard of clay go?
Coverage depends only on depth. The deeper the layer, the less area a cubic yard covers. The suggested depth for clay is 6 to 12 inches, and 6 inches is a common choice.
| Depth (inches) | Square feet covered | Square yards covered |
|---|---|---|
| 1 | 324 | 36.0 |
| 2 | 162 | 18.0 |
| 3 | 108 | 12.0 |
| 4 | 81 | 9.0 |
| 6 | 54 | 6.0 |
| 8 | 40 | 4.5 |
| 12 | 27 | 3.0 |
Clay needed for common areas at 6 inches deep
| Area | Square feet | Cubic yards | US tons |
|---|---|---|---|
| 5 by 5 ft | 25 | 0.46 | 0.62 |
| 8 by 10 ft | 80 | 1.48 | 2.00 |
| 10 by 10 ft | 100 | 1.85 | 2.50 |
| 10 by 20 ft | 200 | 3.70 | 5.00 |
| 12 by 12 ft | 144 | 2.67 | 3.60 |
| 15 by 20 ft | 300 | 5.56 | 7.50 |
| 20 by 20 ft | 400 | 7.41 | 10.00 |
| 20 by 30 ft | 600 | 11.11 | 15.00 |
| 30 by 40 ft | 1,200 | 22.22 | 30.00 |
| 50 by 50 ft | 2,500 | 46.30 | 62.50 |
Worked example: 20 by 20 feet at 6 inches
The area is 20 feet times 20 feet, or 400 square feet. A depth of 6 inches is 0.50 feet. Volume is 400 times 0.50, which is 200.00 cubic feet. Divide by 27 to get 7.41 cubic yards. At 2,700 pounds per cubic yard that weighs about 10.00 US tons. With 10 percent extra, order 8.15 cubic yards.
Tips for ordering clay
- Clay drains slowly, so do not use it where plant roots need free drainage.
- Compact in thin lifts when sealing a pond or building a berm.
- Wet clay is much heavier than dry clay.
Clay swells when wet and shrinks when dry, which is why compaction and moisture control matter.
Frequently asked questions
How many cubic yards of clay do I need?
Multiply length, width, and depth in feet, then divide by 27. A 20 by 20 foot area at 6 inches deep needs about 7.41 cubic yards.
How much does a cubic yard of clay weigh?
About 2,700 pounds, or 1.35 US tons, as a planning value. Ask your supplier for the exact figure.
How deep should clay be?
Most projects use 6 to 12 inches. 6 inches is a common choice.
How many square feet does a cubic yard of clay cover?
54 square feet at 6 inches deep, and 324 square feet at 1 inch.