With sand, the first question is not how much but which kind: all sand measures the same by volume, but the wrong type fails the job. Once you have the right sand, the amount is the usual conversion: area times depth in inches, divided by 324, gives cubic yards. A 100 square foot paver bed at 1 inch of concrete sand is about 0.3 cubic yards, or 17 of the 50 pound bags.
Here is which sand goes where, the amounts by depth, and the three different materials people lump together as paver sand.
Which sand for which job
This is the decision that matters most, because the right amount of the wrong sand still fails:
| Sand type | Grain | Use |
|---|---|---|
| Concrete / coarse sand | Coarse, angular (ASTM C33) | Paver and flagstone bedding |
| Mason sand | Fine, uniform | Mortar, smooth-set beds |
| Play sand | Washed, fine, clean | Sandboxes, play areas |
| Fill sand | Cheap, unwashed | Backfill, raising grade |
The one that catches people is paver bedding. It must be coarse concrete sand, not play or mason sand: fine rounded grains shift and wash out, and the surface ruts within a season. The sand calculator sets the weight by type and also converts to tons for quarry pricing and bags for small jobs.
Sand by job and depth
Depth is set by the use: a thin screeded layer for bedding, a deep layer for a sandbox. Each row is area x depth / 324 for cubic yards, with 50 pound bags at roughly 0.5 cubic feet each:
| Job | Area | Depth | Cubic yards | 50 lb bags |
|---|---|---|---|---|
| Paver bedding | 100 sq ft | 1 in | 0.31 | 17 |
| Paver bedding | 300 sq ft | 1 in | 0.93 | 50 |
| Sandbox (5 x 5 ft) | 25 sq ft | 6 in | 0.46 | 25 |
| Sandbox (8 x 8 ft) | 64 sq ft | 6 in | 1.19 | 64 |
Order a little extra for bedding work: screeding always consumes more than the math, since you overfill slightly before striking it flat.
Bags or bulk
A cubic yard of sand equals 54 of the 50 pound bags, so the crossover comes fast. Bags suit a sandbox or a short run of paver bedding. Anything approaching a full yard should be bulk, for both price and your back.
Sand is heavy: a cubic yard of dry sand runs 2,600 to 2,800 pounds, and wet sand can pass 3,200. That is more than a half-ton pickup should carry, so have bulk sand delivered or haul it in small loads of well under a yard at a time.
The three materials people call "paver sand"
Most of the confusion around sand under pavers is that three different materials get the same nickname, and they are not interchangeable:
- Bedding sand is the 1 inch leveling layer directly under the pavers: coarse concrete sand, screeded flat.
- Joint sand is swept into the gaps between pavers after laying. The standard is polymeric sand, a different product sold in small bags that hardens to resist weeds and washout. The sand calculator does not estimate it; it is sold by coverage on the bag.
- Base is not sand at all. It is 4 to 6 inches of compacted crushed gravel, and it carries the load.
Mix these up (play sand for bedding, or sand where gravel belongs) and the patio settles unevenly no matter how good the pavers are.
Sand is the leveling layer, not the structure
The most expensive version of the base mistake is laying pavers on a thick bed of sand with no gravel underneath. Sand cannot carry a load: it is only the thin, screedable layer that lets you set each paver to an even height.
The structure is the compacted gravel below. Pavers on sand alone rut and settle within a year or two, especially where water moves through the soil. The paver patio base guide walks through the full layer stack in order, how many pavers you need covers the count on top, and the gravel calculator sizes the base that does the actual work.