Types of Gravel Explained: Pea Gravel, #57, Crusher Run, River Rock and More

Walk into a stone yard and you'll see bins labelled with numbers, nicknames and regional terms that can be confusing. Most of them fall into a few families. The two questions that matter are: is the stone crushed (angular) or natural (rounded), and does it contain fines (dust and small particles)? Those two properties decide whether it packs into a hard surface or stays loose and drains freely.

Angular vs. rounded stone

Crushed stone has sharp, fractured faces that lock together under pressure, which makes it stable for driveways and bases. Natural gravel such as pea gravel or river rock has been tumbled smooth by water. It feels nice underfoot and looks decorative, but the round pieces roll against each other and never fully stabilize.

Common gravel types

Type	Size	Shape / fines	Best uses
Pea gravel	⅛–⅜ in	Rounded, no fines	Patios, paths, play areas, around pavers
#8 stone	about ⅜ in	Angular, washed	Paver joints, drainage, concrete mix
#57 stone	about ¾–1 in	Angular, washed	Drainage, French drains, driveway middle layer, under slabs
#3 stone	about 1½–2½ in	Angular, washed	Driveway base, construction entrances
Crusher run (also called road base, dense grade aggregate, #411 in some regions)	up to ¾–1 in plus dust	Angular with fines	Compacted base under pavers and driveways, driveway surface
River rock	¾–3 in and larger	Rounded, smooth	Decorative beds, dry creek beds, around downspouts
Decomposed granite	sand-sized to ¼ in	Fine, compacts	Paths, xeriscape patios, around trees
Lava rock	½–2 in	Porous, light	Decorative mulch substitute, fire pits
Riprap	6 in to 2 ft	Large angular	Erosion control on banks and ditches

The numbered sizes (#3, #57, #8) come from standard aggregate gradations used by many US state transportation departments, but what a quarry calls "#57" can vary slightly. If precise size matters, ask for the product's gradation sheet.

Does stone type change how much you need?

The volume you need depends only on area and depth. The weight depends on the stone's density, which is why the gravel calculator asks for a type. Typical loose densities range from about 1,300 lb per cubic yard for lava rock to around 3,000 lb for crusher run. Ordering 5 yards of lava rock is about 3 tons; 5 yards of crusher run is closer to 7½.

Matching stone to the job

Driveways

Use angular stone in layers: a coarse base, #57 in the middle, and crusher run on top so the surface packs hard. See how much gravel for a driveway.

Walkways and patios

Pea gravel and decomposed granite are comfortable to walk on. Pea gravel needs solid edging and benefits from a stabilizing grid; decomposed granite compacts on its own but can track indoors when wet.

Drainage

Washed stone without fines, such as #57, lets water flow through the gaps. Crusher run would clog. See gravel for drainage and French drains.

Under concrete and pavers

A compacted layer of crusher run or #57 gives a firm, draining base. The concrete calculator helps size the slab itself.

Washed vs. unwashed

Washed stone has had the dust rinsed off. It looks cleaner and drains better, and it costs a little more. Unwashed stone and crusher run contain fines that bind when compacted, which is good for a base and bad for a drain.

Color and appearance

Stone color depends on the local rock: limestone is gray to white, granite can be pink or gray, river rock comes in mixed tans and browns. Wet stone looks darker, so view samples both wet and dry. Imported decorative stone costs much more than local quarry stone, often several times as much per ton.

Quick guide

Need it to pack hard? Choose angular stone with fines.
Need water to pass through? Choose washed angular stone.
Need it to look soft and decorative? Choose rounded stone with edging.