Unit Weight of Gravel and Crushed Stone

Reference

The number depends on which side of the truck you stand on: loose in the box or compacted in the road, and the gap between the two is about 40 percent.

1600 loose to 2200 kg per cubic meter compacted
Loose gravel or clear stone, dry1400 to 1700 kg/m3
Crusher run, loose1600 to 1900 kg/m3
Compacted granular base, in place2100 to 2300 kg/m3
In force unitsabout 15 to 22 kN per cubic meter
US customary90 to 105 loose, up to 145 lb per cubic foot compacted
Ordering ruleabout 2.2 t per compacted cubic meter

Notes for design and site

Voids explain the whole table. Solid rock sits at 2650 to 2700 kg per cubic meter, so a loose pile at 1600 is about 40 percent air. Compaction squeezes a well graded crushed base to 2100 to 2300, under 20 percent voids, which is why the proctor maximum for a good crushed rock lands in the same band.

Clear stone is the deliberate exception. A single size 19 mm aggregate cannot pack much tighter than it lands, staying near 1600 to 1750 even after seating, and that is the point: the voids it keeps are the drainage path around a pipe or behind a wall.

The purchasing consequence is blunt. One compacted cubic meter of base takes about 2.2 tonnes of material, not the 1.6 a loose measure suggests, so crews that order by loose volume come up a third short. Run the volume first, convert at the compacted number, then add waste.

Related Calculators and Reference