How to Calculate Sand
Sand is the workhorse of construction and landscape projects - paver bases, sandboxes, mortar mixes, pipe bedding, concrete fill, and polymeric joint sand all demand different grades. Getting the volume right is only half the battle; the other half is choosing the correct sand type. Using play sand in mortar or masonry sand under pavers leads to failure within a single season.
Volume Formula
Like all bulk materials, sand volume is length times width times depth, converted to cubic yards (or cubic meters) since suppliers price by that unit:
Weight and Tonnage
Sand weighs more than most bulk materials. Loose dry sand runs about 90 lb/cu ft; packed or wet sand can hit 120 lb/cu ft. At 100 lb/cu ft (the typical moist delivery weight), one cubic yard equals roughly 2,700 pounds or 1.35 US tons:
Sand Types and Their Uses
Using the wrong sand type is one of the most common causes of premature project failure. Polymeric sand in a sandbox is a choking hazard; play sand in mortar produces crumbling joints. Match the sand to the job:
| Sand Type | Grain | Best Use |
|---|---|---|
| Masonry Sand | Fine, uniform | Mortar, stucco, grout, brick |
| Concrete Sand | Coarse, angular | Concrete mix, pipe bedding |
| Play Sand | Washed, fine | Sandboxes, play areas only |
| Paver Setting Sand | Coarse washed | Paver bedding layer (1") |
| Polymeric Sand | Fine + polymer binder | Paver joints - hardens with water |
| All-Purpose | Mixed gradation | General landscape, traction |
| Fill Sand | Unwashed, mixed | Site fill, utility trenches |
Paver Base Build-Up
For patios and walkways, the sand layer sits between the gravel base and the pavers. Order:
- Gravel base: 4 to 6 inches of compacted 3/4 minus crushed stone
- Bedding sand: 1 inch of coarse washed concrete sand - screed flat, do not compact
- Pavers: 2 3/8 inch standard thickness
- Polymeric joint sand: swept into joints, activated with fine water spray
Sandbox Sand Requirements
For a 6x6 ft sandbox at 8 inches deep, plan on about 0.89 cubic yards - roughly 1 ton or 36 fifty-pound bags of play sand. Always verify the bag is labeled "play sand" with non-toxic certification. Never use:
- Construction sand - may contain crystalline silica dust (lung hazard)
- Mason sand - dyes skin and clothes when wet
- Beach sand - salty, contaminated, unpredictable
- Polymeric sand - hardens into a choking hazard on contact with saliva