How to calculate sand
Cubic feet = length × width × depth (all in feet)
Cubic yards = cubic feet ÷ 27
Tons = cubic yards × 1.35
50 lb bags = cubic feet ÷ 0.5
Example: a sandbox 8 × 8 ft, filled 12 in deep.
- Volume: 8 × 8 × 1 = 64 cu ft
- Cubic yards: 64 ÷ 27 = 2.37
- Weight: 2.37 × 1.35 = 3.2 tons (6,400 lb)
- Bags: 64 ÷ 0.5 = 128 bags of 50 lb
At that size, compare bulk and bags: 128 bags at about $6.35 come to about $813, while 3.2 tons at HomeGuide’s $15 to $50 a ton is $48 to $160 plus delivery.
How heavy is sand?
The calculator uses 1.35 tons per cubic yard (100 lb per cubic foot) for dry sand. Published figures for loose dry sand run from about 1.2 tons per cubic yard (Caterpillar) to about 1.37 (Missouri DOT); compacted, the Missouri DOT puts it at 109 lb per cubic foot, about 1.47 tons. Water adds weight, so a damp load from the yard weighs more than the same volume dry. Change the density if your supplier gives you a figure.
The 0.5 cu ft bag matches that density: 50 lb at 100 lb per cubic foot is half a cubic foot.
Which sand?
HomeGuide lists the common types: fill sand for leveling and backfill, coarse concrete sand for mixing concrete and drainage layers, washed paver sand for bedding and joints, and play sand for sandboxes. For the joints between pavers, polymeric sand comes in bags rated by area; the paver calculator counts those. For gravel or crushed stone, use the gravel calculator.