Sand sold by the yard, by the bag or by the ton is still the same volume underneath. The depth decides how much of it you need, and depth is the one number that is different for every job.
Volume (cu ft) = length (ft) × width (ft) × depth (ft)
Depth in feet = depth in inches ÷ 12
Volume (cu yd) = cu ft ÷ 27
Order = volume × (1 + allowance)
Two jobs, same formula
A thin bedding layer under pavers and a sandbox are both flat boxes of sand. The depths below are examples, not recommendations: pick the depth for your own job.
| Job | Area and depth | Volume to order | Bags |
|---|---|---|---|
| Bedding layer (example) | 16 × 12 ft, 1 in deep | 0.65 yd³ | 36 × 0.5 cu ft bags |
| Sandbox (example) | 4 × 4 ft, 6 in deep | 0.33 yd³ | 18 × 0.5 cu ft bags |
This example assumes
- 0.5 cu ft bags
- 10% extra allowance, an editable planning default
The bedding layer is only an inch deep but spreads over 192 sq ft, so it needs more sand than the sandbox, which is deeper and far smaller. A quick way to see this: area × depth is what counts, not either one alone.
Weight is a separate estimate
Sand is often sold by weight, but the weight of a cubic yard depends on the sand and how wet it is. The planner leaves the weight line off until you give it a density. If your supplier says a cubic yard weighs a particular amount, enter that and the planner shows an estimated weight. For a 4 × 4 ft sandbox at 6 inches with a density of 1.35 tons per cubic yard, for example, the planner’s working shows ≈ 0.44 tons (estimated from your density of 1.35 tons / yd³). That density is an input, not a standard.
What changes the estimate?
- The depth you choose, which scales everything
- The allowance for settling and uneven ground
- Bag volume, or bulk delivery by the yard
- Density and moisture, if you are converting to weight
- The sand type your project calls for, which this estimate does not choose
Paver sand has its own guide
The bedding layer under pavers is one use of the same math, with its own considerations. See how much bedding sand for pavers.