The quick version
Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
Divide by 27 to get cubic yards. For weight, play sand runs about 1.25 tons per cubic yard, which is the figure the sand calculator uses. Real sand varies with moisture and the supplier, so treat the weight as a guide and ask what your yard's sand weighs.
Sand for common sandbox sizes
Each row shows cubic feet, cubic yards and the approximate tons of play sand. No extra is added.
| Sandbox | Depth | Cubic feet | Cubic yards | Tons (about) |
|---|---|---|---|---|
| 4 x 4 ft | 6 in | 8.0 | 0.30 | 0.37 |
| 4 x 4 ft | 8 in | 10.7 | 0.40 | 0.49 |
| 4 x 4 ft | 12 in | 16.0 | 0.59 | 0.74 |
| 5 x 5 ft | 6 in | 12.5 | 0.46 | 0.58 |
| 5 x 5 ft | 8 in | 16.7 | 0.62 | 0.77 |
| 5 x 5 ft | 12 in | 25.0 | 0.93 | 1.16 |
| 6 x 6 ft | 6 in | 18.0 | 0.67 | 0.83 |
| 6 x 6 ft | 8 in | 24.0 | 0.89 | 1.11 |
| 6 x 6 ft | 12 in | 36.0 | 1.33 | 1.67 |
| 8 x 8 ft | 6 in | 32.0 | 1.19 | 1.48 |
| 8 x 8 ft | 8 in | 42.7 | 1.58 | 1.98 |
| 8 x 8 ft | 12 in | 64.0 | 2.37 | 2.96 |
| 10 x 10 ft | 6 in | 50.0 | 1.85 | 2.31 |
| 10 x 10 ft | 8 in | 66.7 | 2.47 | 3.09 |
| 10 x 10 ft | 12 in | 100.0 | 3.70 | 4.63 |
How deep should it be?
That one is yours to decide, and the table lets you see what each choice costs. Six inches is a thin layer. Twelve means more to dig, and more to buy. The size of the box and the age of the kids matter more than any rule.
Whatever depth you pick, do the math before you go to the supplier. A 10 by 10 ft box at 12 inches takes 3.7 cubic yards, which is more than most pickup trucks should carry.
Round box or odd shape
For a round sandbox, find the area first: π × radius². A 6 ft wide circle has a 3 ft radius, so its area is 28.3 sq ft, and at 8 inches deep it needs 18.8 cubic feet. For a mix of shapes, add up the pieces. The how to calculate cubic yards page walks through each one.
Buying it
Small boxes are easy to fill from bags. Larger ones are cheaper from a supplier by the cubic yard or the ton, and the tons to cubic yards calculator converts between the two. Order a bit more than the table says. Sand settles, and some always ends up on the grass.
Frequently asked questions
How much sand do I need for a 4x4 sandbox?
At 6 inches deep, 8 cubic feet, which is 0.30 cubic yards. At 12 inches, 16 cubic feet.
How many cubic feet of sand is in a cubic yard?
27.
How much does a cubic yard of play sand weigh?
About 1.25 tons with the figure used on this site. Moisture changes it, so ask your supplier.
How do I calculate sand for a round sandbox?
Multiply pi by the radius squared to get the area, then by the depth in feet.