The sand calculator turns an area and a depth into cubic yards, then into dry weight and 50-lb bags. Weight comes as a range, because sand weighs what its packing makes it weigh: the Federal Highway Administration's soils manual puts clean, uniform sand at 1.33 to 1.89 times the weight of water when dry, loosest to densest.
Use it for a sandbox, a leveling layer or bedding sand bought on its own. For the sand under pavers, the paver calculator sizes the bedding layer and the base together.
How to use it
- 01
Measure the box or bed
The sandbox, the patch to level or the strip to bed, in feet. A round sandbox is its diameter squared times 0.79, so enter the diameter as both sides and take 79 percent of the answer.
- 02
Decide the sand depth
Bedding under pavers is screeded to a nominal inch; a sandbox or a leveling fill is whatever depth you mean to leave, entered in inches.
- 03
Pick the sand
Play and masonry sand are uniform, one grain size; concrete or paver sand runs from fine to coarse. The FHWA table gives the two different weight ranges, so the choice moves the tons and the bags, never the volume. The paving association's guide says masonry sand should never be used as bedding under pavers.
- 04
Set a waste allowance
Ten percent by default, for spillage and the sand that stays in the bag or the wheelbarrow.
How the math works
Volume
A 10-by-10 area 2 inches deep holds 16.7 cubic feet of sand, 10 × 10 × 2 ÷ 12; divided by 27, that is 0.62 cubic yards.
Weight
Dry pounds = cubic feet × (1 + waste) × the multiple of water × 62.4. For uniform sand the multiple runs from 1.33 loosest to 1.89 densest: 83 to 118 pounds a cubic foot, or 1.12 to 1.59 tons a cubic yard. The same 10-by-10 area at 2 inches, with ten percent waste, weighs 1,522 to 2,162 pounds dry.
Bags
Bags = dry pounds ÷ 50, rounded up, at each end of the range: 31 to 44 bags of 50 pounds for the example. Poured sand sits near the low end and compacted sand near the high one, so buy toward the high end if you will tamp it.
Wet sand
The table is for dry sand. Sand from a stockpile is usually damp, and moisture changes both its weight and how it packs, so a supplier's weight for its own sand beats any table. Buying by the cubic yard sidesteps the question.
Worked examples
| Job | Cubic yards | Play or masonry sand, tons | Concrete or paver sand, tons | 50-lb bags, play sand |
|---|---|---|---|---|
| 1 cubic yard | 1.00 | 1.12–1.59 | 1.15–1.86 | 45–64 |
| 2 cubic yards | 2.00 | 2.24–3.18 | 2.29–3.72 | 90–128 |
| Sandbox, 8 × 8 ft, 12 in | 2.37 | 2.66–3.77 | 2.72–4.41 | 107–151 |
| Leveling layer, 10 × 10 ft, 2 in | 0.62 | 0.69–0.98 | 0.71–1.15 | 28–40 |
| Paver bedding, 12 × 12 ft, 1 in | 0.44 | 0.50–0.71 | 0.51–0.83 | 20–29 |
Each range runs from loosest to densest packing, from the FHWA soils manual's dry unit weights: 1.33 to 1.89 times water for clean uniform sand and 1.36 to 2.21 for sand graded fine to coarse. Add the calculator's waste allowance before ordering. Damp sand from a pile weighs differently; the supplier's figure for its own sand governs the order.
Where the number goes wrong
- Using masonry sand, limestone screenings or stone dust as paver bedding. The paving association's guide rules out all three; screenings and stone dust often do not compact uniformly and can hold water in the bedding layer.
- Screeding bedding sand thicker to hide an uneven base. The same guide says the unevenness reflects through to the surface over time.
- Ordering by the ton from a dry-sand figure when the pile is wet.
Questions people ask
How much does a cubic yard of sand weigh?
Dry, 1.12 to 1.59 tons for clean uniform sand and 1.15 to 1.86 tons for sand graded fine to coarse, loosest to densest, by the FHWA table. Damp sand from a pile differs; the supplier's weight for its own sand governs.
How many 50-lb bags of sand are in a cubic yard?
At the FHWA range for clean uniform sand, 45 to 64: 27 cubic feet at 83 to 118 pounds each, divided by 50.
How thick should paver bedding sand be?
A nominal inch, screeded and left uncompacted before the pavers go down, per the paving association's installation guide. It should not be used to make up for an uneven base.