How to calculate sand
Length × width × depth gives the volume: multiply square feet by the depth in inches and divide by 12 for cubic feet, then by 27 for cubic yards. Bags are sold by weight (50, 60, 70 lb) or by volume (0.5 cu ft); bagged sand runs about 100 lb per cubic foot, so a 50 lb bag is about half a cubic foot. Bulk sand is sold by the ton or the yard at roughly 1.4 tons per yard.
Worked examples: a 10×10 ft paver bed 1 in deep is 100 ÷ 12 = 8.33 cu ft — 17 bags of 0.5 cu ft. A 5×5 ft sandbox filled 6 in deep is 12.5 cu ft — 25 bags of 50 lb, or 28 with 10% extra for spillage.
What a yard of sand weighs
| Source | Tons per cubic yard |
|---|---|
| Vulcan Materials (by geology) | 1.35–1.49 |
| Martin Marietta (fine aggregate) | 1.44–1.47 |
| Kokosing (Ohio, all sands) | 1.5 |
| Mulch Pros scale — mason & river sand | 1.3 |
| MI LTAP highway tables — loose sand | 1.32–1.48 |
The calculator uses 1.4 tons for damp, loose sand. Wet sand weighs more and dry sand less; the volume you need doesn't change. See bags in a cubic yard and bags in a ton.
Which sand?
- Play sand: Washed and screened for sandboxes (Quikrete Premium Play Sand: 50 lb bags, 56 per pallet).
- All-purpose sand: Washed coarse sand meeting ASTM C33 (Quikrete No. 1152). Mixing, leveling, under slabs.
- Mason sand: Fine, uniform sand for mortar and sandboxes; sold bulk at landscape yards.
- Paver leveling sand (coarse concrete sand): The 1 in screeded bed under pavers. Unilock specifies coarse concrete sand over a crusher-run base.
How deep?
- Under pavers: a 1 in screeded bed (Unilock); Quikrete allows 1–2 in. Thicker beds let pavers settle unevenly.
- Under a slab: the IRC allows a 4 in base of clean graded sand, gravel or crushed stone.
- Playgrounds: CPSC rates 9 in of sand for falls up to only 4 ft — start at 12 in, since loose fill compresses at least 25%.
- Sandboxes: pick the depth you want to dig in; the calculator converts it to bags.
Bags or bulk?
Bagged play and all-purpose sand costs about $4.67–$6.20 per 50 lb bag — roughly $250–$335 per cubic yard. Bulk concrete sand is $68.95 a yard in Sacramento (Roseville Rock Supply) and mason sand $69.95 a ton in north Atlanta (Mulch Pros), plus delivery. For a sandbox or a paver bed, bags are simpler; past a yard or so, bulk wins even with a delivery fee. A pallet of Quikrete sand is 56 bags of 50 lb — 28 cu ft, about one cubic yard and 1.4 tons.
Getting it home
A cubic yard of damp sand weighs about 2,800 lb, nearly three times the nominal payload of a half-ton pickup — check the Tire & Loading sticker on the door jamb before loading bags or bulk. Fifty-four 50 lb bags is 2,700 lb, so even a bagged yard is two or three trips. For bulk, a single-axle dump truck carries about 3.6 cubic yards and a tandem about 12.9. Ask the yard whether it sells sand by the ton (as Mulch Pros in Georgia does) or by the yard (as Roseville Rock Supply in California does) and convert before comparing prices: at 1.4 tons per yard, $69.95 a ton is about $98 a yard.
Measuring a sandbox or play area
Measure the inside of the frame, not the outside of the boards, and decide on the finished sand level before you buy: a sandbox filled to within a couple of inches of the top holds less than its nominal height. For round sandboxes, use the diameter — the calculator applies π × radius². Under play equipment, the CPSC use zone extends 6 ft beyond the equipment on every side, so a 10×12 ft play set needs sand over 22×24 ft.
Common mistakes
- Assuming a 50 lb bag is a cubic foot — it is about half of one.
- Compacting paver bedding sand before laying; it is screeded loose and the pavers are compacted into it.
- Using sand under tall play equipment, where CPSC rates it for only 4 ft falls.
- Loading a yard of sand — about 2,800 lb — into a pickup rated for 1,000 lb.
Building the paver base too? Use the paver base calculator. For gravel, use the gravel calculator; for playground wood chips, the mulch calculator; and for a slab poured on a sand base, the concrete slab calculator.