Types of Gravel: Complete Guide to Sizes & Uses
Before you run the numbers through the pea gravel calculator, it helps to know what you're actually ordering. Here's a quick reference for the most common gravel types, their sizes, and what each is best used for.
"Gravel" isn't one product — it's a category covering everything from smooth, pea-sized decorative stone to dense, dust-filled base material rated for driveway traffic. Suppliers usually sort it two ways: by how it was formed (naturally rounded by water, or mechanically crushed with angular edges) and by size grade, often using standardized screen numbers like #57 or #411. Knowing both tells you not just what a material looks like, but what it's structurally suited for.
Pea Gravel
Pea gravel is small, naturally rounded stone — smoothed by water erosion rather than machine-crushed — typically 3/8 to 1/2 inch in diameter, roughly the size of a pea. It's usually a mix of tan, gray, white, and rust tones rather than one uniform color, which is part of its appeal for decorative use. Because it's rounded rather than angular, it's comfortable to walk on barefoot and doesn't lock together the way crushed stone does, so it stays loose underfoot — good for pathways and play areas, but not something you'd use as a load-bearing driveway base on its own.
| Size class | Inches | Millimeters |
|---|---|---|
| Standard pea gravel | 3/8"–1/2" | ~9.5–12.7 mm |
| Small / fine pea gravel | 1/4"–3/8" | ~6–9.5 mm |
Best for walkways, patios, playgrounds, and as a low-maintenance ground cover or mulch alternative in garden beds. Run your dimensions through the pea gravel calculator for exact tons, yards, and bags.
Crushed Stone #57 & #411
Crushed stone is quarried rock mechanically broken into angular fragments, then screened into standardized size grades — the numbers (#57, #411, #8, and others) come from AASHTO and state DOT screen specifications, and they show up on nearly every supplier's price list.
#57 stone is clean, washed, angular stone roughly 3/4" to 1" with the fines screened out — no dust or small particles left in the mix. That open, uniform gradation leaves gaps between stones, which is exactly what makes it good for drainage: water moves through it freely instead of pooling. It's the standard choice for French drains, drainage beds, and as a base layer under driveways and patios where water needs somewhere to go.
#411 stone (also sold as "crusher run" or dense-graded aggregate in some regions) is the opposite: a graded mix of crushed stone sizes down to fine stone dust. The small particles fill the gaps between larger stones, so it compacts into a dense, low-permeability surface rather than draining. That makes #411 the better choice for a compacted driveway base or surface course, where you want a solid, stable footing rather than water passing through.
Crusher Run
Crusher run is a mix of crushed stone, sand, and stone dust straight off the crusher, unscreened into a single clean size — the fines fill the voids between larger stones so the whole mix compacts tightly into a hard, stable surface. It's sold under different names depending on the region: crusher run, crush and run, quarry process (QP), dense-graded aggregate (DGA), and road base all describe roughly the same product, and in practice it overlaps heavily with #411 stone. Whatever it's called locally, it's the standard base material for gravel driveways, under pavers and retaining walls, and anywhere you need a compacted, load-bearing surface rather than a decorative or draining one. See the gravel driveway calculator for how it fits into a full driveway layer build.
River Rock
Like pea gravel, river rock is naturally rounded by water rather than crushed — the difference is size. River rock starts around 1 inch and runs up to 5 inches or more, typically sold in size grades of 1"–2", 2"–3", and 3"–5". Its rounded shape and mixed earth tones make it a popular choice for dry creek beds, drainage swales, and decorative borders where you want fewer, larger stones rather than a fine, even surface. Because rounded stones don't interlock as tightly as crushed stone, river rock used for drainage often needs a geotextile fabric underneath to stop it migrating into the soil. See the river rock calculator for size-specific coverage and depth guidance.
Limestone Gravel
In regions with limestone bedrock — much of the Midwest and parts of the South — crushed limestone is often the default "gravel" sold locally, simply because it's the closest quarry material. It's typically light gray, tan, or off-white, and shows up in two forms: as a coarser crushed base material (functionally similar to #57 or #411 stone) and as fine limestone screenings or "limestone dust," a compacted, walkable surface popular for pathways and driveway toppings. Limestone is generally one of the more affordable gravel options since it's abundant and doesn't require long-distance shipping in limestone-heavy regions, and it compacts well for bases and paths. It is somewhat softer than granite-based crushed stone, though, so it can break down a little faster under heavy, repeated vehicle traffic or in freeze-thaw climates.
Gravel Comparison Chart
A side-by-side view of everything above — use it to compare sizes and typical uses at a glance before you commit to a material.
| Type | Typical size | Density | Best for |
|---|---|---|---|
| Pea gravel | 3/8"–1/2" | ~1.4 tons/yd³ | Walkways, patios, playgrounds, ground cover |
| Crushed stone (#57) | 3/4"–1" | ~1.5 tons/yd³ | Drainage, French drains, base layers |
| Crushed stone (#411) | Dust–3/4" | ~1.5 tons/yd³ | Compacted driveway base/surface |
| Crusher run / road base | Mixed, dust to 3/4" | ~1.5 tons/yd³ | Compacted driveway and road bases |
| River rock | 1"–5"+ | ~1.5 tons/yd³ | Drainage beds, borders, dry creek beds |
| Limestone gravel | Dust–1" | ~1.3–1.5 tons/yd³ | Paths, driveway base, budget-friendly fill |
| Decorative/landscape gravel | 1/4"–1" | ~1.4 tons/yd³ | Garden beds, mulch alternative, accents |
How to Choose by Project
- Walkway or patio: pea gravel over a compacted crushed stone base.
- Driveway base layer: #57 crushed stone or crusher run, compacted.
- Driveway surface layer: crusher run/#411 for a solid drivable finish, or a thin pea gravel top layer for looks.
- Drainage bed or French drain: washed #57 crushed stone, or river rock for a more visible drainage feature.
- Dry creek bed: 3"–5" river rock, sometimes mixed with 1"–2" rock along the banks.
- Garden bed or mulch alternative: pea gravel or decorative landscape gravel.
- Budget-conscious base or fill: limestone gravel where locally available.
Frequently asked questions
What size is pea gravel?
Pea gravel is typically 3/8 inch to 1/2 inch in diameter (about 9.5–12.7 mm) — roughly the size of a pea, which is where it gets its name. It's naturally rounded and smooth from water erosion.
What's the difference between pea gravel and river rock?
Pea gravel is smaller (3/8–1/2 inch) and used for pathways, patios and playgrounds. River rock is larger (1 inch and up) and used for drainage beds, borders and bigger decorative features.
What is crushed stone used for?
Crushed stone has angular, machine-broken edges that interlock when compacted, making it the standard choice for driveway bases, under patios, and drainage applications.
What's the difference between crusher run and crushed stone?
Crushed stone like #57 is a clean, single size with the fines screened out, so it drains well. Crusher run (similar to #411) includes stone dust and fine particles that fill the gaps between larger stones, so it compacts tight instead of draining — better for a solid driveway base than for drainage.
Is limestone gravel good for a driveway?
Yes, and in limestone-producing regions it's often the most affordable option. It compacts well as a base or surface layer, though it's somewhat softer than granite-based crushed stone and can wear faster under heavy repeated traffic or in freeze-thaw climates.
What is #57 stone?
#57 is a standard crushed stone grade, roughly 3/4 to 1 inch, washed clean of fine particles. The open gaps between stones let water pass through freely, which is why it's the go-to material for drainage beds and French drains.
What's the cheapest type of gravel?
Crusher run, road base, and limestone gravel are usually the least expensive, since they require the least processing and are often quarried locally. Washed, screened, or naturally rounded materials like pea gravel and river rock cost more — see the gravel cost calculator for current price ranges by material.