Types of Gravel and Sizes: Which Should You Use?
Last updated
Gravel names vary by region and supplier, but a few materials cover most projects. Choosing the right one affects how well the surface holds up, how it drains, and how much you pay. This guide explains what the names and numbers mean, and which gravel suits each job.
The two things that matter most
Almost every gravel choice comes down to two properties.
- Shape: angular or rounded. Crushed stone is quarried rock broken by machines, so it has sharp, fractured faces that lock together when compacted. Natural gravel, pea gravel, and river rock have been rounded by water. They roll against each other, which makes them comfortable underfoot but unstable under wheels.
- Clean or with fines. Clean (washed) stone is screened to one size, leaving open spaces between the pieces for water to flow through. Stone with fines, such as crusher run, #411, and anything sold as "minus", includes dust and small pieces that fill those spaces, so it compacts into a hard, stable layer that sheds water rather than draining it.
Driveway bases want angular stone with fines. Drainage wants angular stone without them. Paths and decorative beds can use rounded stone.
Crushed stone numbers explained
Crushed stone is often sold by number. In the US the numbers come from a standard size chart (ASTM D448, which state transportation departments also use), and lower numbers mean bigger stone. Each number is a range rather than a single size: #57, for example, runs from about 1 in down to 3/16 in, with most pieces between 1/2 and 3/4 in.
| Number | Approximate size | Common uses |
|---|---|---|
| #3 | 1 to 2 in | Driveway base, bottom layer of a three-layer driveway, construction entrances |
| #4 | 3/4 to 1-1/2 in | Driveway base, drainage around large pipes |
| #57 | 3/16 to 1 in (mostly 1/2–3/4 in) | Driveways, French drains, slab bases, behind retaining walls |
| #67 | 3/16 to 3/4 in | Concrete mixes, drainage, finer driveway surfaces |
| #8 | 3/32 to 3/8 in | Paths, permeable paver bedding, pipe bedding |
| #10 (screenings) | 3/16 in down to dust | Leveling under flagstone, blending into #411 |
Sizes are approximate. Some states and quarries use their own numbering, so ask for the gradation sheet when size really matters, such as for drainage or paver bedding.
Common gravel types at a glance
| Type | Typical size | Best for | Notes |
|---|---|---|---|
| Crushed stone (#57) | About 3/4 in | Driveways, drainage, base layers | Angular, locks together when compacted |
| Crusher run | 3/4 in minus, with fines | Driveway and patio base | Packs very firm; drains poorly compared with clean stone |
| #411 | #57 mixed with stone dust | Driveway top layer | Compacts into a smooth, hard surface |
| Pea gravel | About 3/8 in, rounded | Paths, patios, dog runs, decorative beds | Smooth and comfortable, but shifts underfoot |
| River rock | 1–3 in and larger | Decorative beds, dry creek beds, splash areas | Rounded and attractive, not for driving on |
| Decomposed granite | 1/4 in and smaller | Garden paths, patios | Compacts to a firm surface; stabilized versions resist washing out |
| Recycled crushed concrete | Usually 3/4 in minus | Driveway and road base | Often cheaper than quarried stone; quality varies, so look at a load first |
| Rip rap | 6 in and larger | Erosion control on slopes, banks, and culvert outlets | Too big to walk or drive on |
Sizes are approximate. Grading names and stone sizes differ between suppliers, so confirm what you are buying.
Crusher run goes by many names
The dense, compactable base material most driveways are built on is sold under many local names: crusher run, crush and run, road base, 3/4 in minus, dense-grade aggregate (DGA), and state designations such as 21AA in Michigan, Class 5 in Minnesota, CA-6 in Illinois, and Item 4 in New York. They aren't identical, since each has its own mix of sizes, but they do the same job. Tell the supplier what you're building and they'll point you to their equivalent.
Which gravel for which project
| Project | Use | Why |
|---|---|---|
| Driveway base | #3 or #4 stone, crusher run, or recycled concrete | Large angular stone spreads the load and compacts |
| Driveway surface | Crusher run, #411, or #57 | Fines pack into a hard surface; #57 drains better but stays looser |
| French drain | Clean, washed #57 wrapped in non-woven fabric | Open gaps let water reach the pipe; the fabric keeps soil out |
| Behind a retaining wall | Clean #57 | Drains water that would otherwise push on the wall |
| Under a concrete slab | Clean #57 or crusher run, 4 in compacted | Firm, even support; clean stone also limits moisture wicking under indoor slabs |
| Under pavers | Crusher run base plus 1 in of concrete sand | Firm base and a smooth bed; permeable pavers use #57 and #8 instead |
| Walkway or garden path | Pea gravel, #8, or decomposed granite | Small stone is comfortable to walk on |
| Dog run | Pea gravel | Smooth on paws, drains fast, and rinses clean |
| Decorative beds | River rock, pea gravel, or colored stone | Holds its look and doesn't break down like mulch |
Layer depths for driveways are in how much gravel for a driveway; slab bases are covered in the concrete slab thickness guide.
Weight and coverage by type
Different stone weighs different amounts per cubic yard, typically between 2,600 and 2,800 pounds. That changes how many tons you order for the same volume. Stone with fines, such as crusher run, packs even denser once compacted, which is why the Driveway Calculator assumes about 2,800 lb per cubic yard for driveway stone. See the gravel coverage chart for the numbers, then use the Gravel Calculator to price your chosen type. For prices, read how much gravel costs.
Buying tips
- Say what it's for. Names vary between suppliers, but "base for a driveway" or "stone for a French drain" gets you the right product anywhere.
- Ask if it's washed. For drainage it should be; for a compacted base it shouldn't be.
- See it first. Many yards have sample bins. For decorative stone, look at it both wet and dry, since the color changes when it's wet.
- Buy decorative stone all at once. Color and size vary between batches, so a second order may not match the first.
- Order each layer separately if you're using different stone for the base and the surface.
Related guides and calculators
Frequently asked questions
Strictly, gravel is naturally rounded stone from rivers and glacial deposits, while crushed stone is quarried rock broken by machines into sharp, angular pieces. Suppliers often call both “gravel”, but the shape matters: angular stone locks together, while rounded stone rolls.