Unit Weight of Sand
The grains barely matter: packing and moisture swing the weight of a cubic meter of sand by half again, and the damp loose state is the one that fools people.
| Dry, loose | 1400 to 1600 kg/m3 |
| Dry, compacted | 1600 to 1800 kg/m3 |
| Damp and loose, bulked | 1250 to 1500 kg/m3 |
| Saturated or wet packed | 1900 to 2100 kg/m3 |
| In force units | roughly 14 to 21 kN per cubic meter |
| US customary | 90 to 130 lb per cubic foot |
| Ordering rule | about 1.6 t per cubic meter, dry |
Notes for design and site
Packing and moisture matter more than mineralogy. The same quartz sand runs 1400 kg per cubic meter loose and dry, 1800 vibrated into place, and 2100 with every void flooded, a 50 percent swing with identical grains.
Damp sand plays a trick called bulking. At 4 to 6 percent moisture, films of water hold the grains apart and a loose pile grows by up to a quarter in volume, dropping the bulk density as low as 1250 kg per cubic meter. Flood it and the structure collapses back. This is why batching concrete by volume with damp sand short changes the mix by 20 percent or more, and why ordering by the tonne sidesteps the whole problem.
On the geotechnical side, loose versus dense is not bookkeeping, it is behaviour: relative density decides whether a sand settles a few millimetres under a footing or keeps rearranging, and the friction angle pages carry the matching strength ranges.
Related Calculators and Reference
- Unit Weight of Soil: the full table across soil types.
- Relative Density Calculator: how loose or dense actually gets quantified.
- Friction Angle of Loose Sand: strength values at the light end of the table.
- Friction Angle of Dense Sand: strength at the heavy end.
- Concrete Mix Volume and Quantity Estimator: where the sand tonnage ends up.
- Sand Calculator: tons, cubic yards and bags of sand for pavers, sandboxes and pool pads.
- ASTM International: aggregate specifications, including C33 for concrete sand.