Gravel Size Chart: Pea Gravel to Crushed Stone
Everything you need to know about gravel size chart.
Gravel Size Chart: The Direct Answer
A gravel size chart sorts stone by diameter, from fine screenings smaller than 1/8 inch up to river rock several inches across. Most residential projects fall into three families: pea gravel, which runs larger and smoother. Knowing where your project sits on that scale is the fastest way to pick the right size before you order.
Gravel sizes are usually described one of two ways: a fraction of an inch (3/8 inch, 3/4 inch, 1.5 inch) or an industry size number used by quarries and departments of transportation. Both describe the same thing, the typical diameter of the stone in a load, since no batch is perfectly uniform. A stated size is a target, not an exact cutoff, so expect a small percentage of pieces above and below the listed range in any delivered load.
Many quarries and transportation departments also label graded stone with a number instead of, or alongside, an inch measurement. The number itself refers to a standard sieve grading rather than a literal inch figure, so two different numbering systems can use different digits for a similar diameter. The safest way to compare is to look at the stated inch range on the product page rather than matching numbers across suppliers.
Details and Variations in Gravel Sizes
Within each material family, size changes what the stone is good for. Smaller stone packs tighter and locks together underfoot, which is why fine gravel shows up in walkways and driveway base layers. Larger stone leaves more open space between pieces, which is why it moves water well in drainage lines and French drains but shifts more underfoot. Shape matters as much as diameter. Angular, crushed pieces of a given size interlock and hold a compacted shape, while rounded, water worn pieces of the same size roll against each other and stay loose no matter how deep the layer is.
Whether the fines are left in or screened out changes performance too. A minus product keeps the dust and small fragments that fill the gaps between larger pieces, so it compacts into a firm, stable base once tamped and watered. A clean or washed product has those fines removed, so water passes through freely instead of pooling, which is why clean stone is chosen for drainage and minus stone is chosen for bases.
Pea Gravel Sizes
Pea Gravel is naturally rounded and generally runs from about 1/8 inch up to 3/8 inch, close to the size of a garden pea. Its rounded edges make it comfortable to walk on barefoot, which is why it is common in patios, playgrounds and pathway fill.
Crushed Stone Sizes
Crushed Stone is mechanically crushed rather than naturally worn, so the pieces are angular with sharp faces that lock together under weight. It is sold in a range of graded sizes, roughly from 3/8 inch fine stone used for compacted bases up to 1.5 inch stone used for driveways and drainage. A version with fines left in, often labeled as a minus product, compacts hard for a base layer. A clean, washed version with the fines screened out drains freely and is used where water needs to pass through.
River Rock Sizes
River Rock is naturally smoothed by water over time and typically starts around 1 inch, running up to several inches for larger decorative stone and cobble. It does not compact and is not a base material. It is chosen for its look and used in dry creek beds, borders and erosion control on slopes.
Gravel Size Chart by Diameter
The table below lines up common stone categories by typical diameter and what each one is generally used for. Sizes are approximate, since every load includes a range around the target diameter rather than one exact measurement.
| Size Category | Typical Diameter | Common Uses |
|---|---|---|
| Screenings or stone dust | Under 1/8 inch | Leveling under pavers, filling joints |
| Pea gravel | 1/8 to 3/8 inch | Walkways, playgrounds, decorative beds |
| Fine crushed stone | 3/8 to 3/4 inch | Compacted driveway and patio base |
| Standard crushed stone | 3/4 to 1.5 inch | Driveway surfacing, French drains, drainage fields |
| Small river rock | 1 to 3 inches | Dry creek beds, landscape borders |
| Large river rock or cobble | 3 inches and larger | Accent stone, erosion control on slopes |
For a rough volume estimate once you know the depth you need, the standard formula is cubic yards equals length in feet times width in feet times depth in inches, divided by 324. That formula works the same regardless of which size gravel you pick, since it measures space to fill rather than stone count. The gravel calculator runs that math for you if you enter the dimensions of your project.
Mistakes to Avoid When Reading a Gravel Size Chart
- Ordering pea gravel for a driveway base. It is too small and rounded to lock together, so it shifts and ruts under vehicle weight instead of compacting.
- Ordering large river rock for a drainage trench that needs a filter fabric or tight fit. Big stone leaves gaps that let fines wash in and clog the system over time.
- Assuming clean stone and minus stone of the same size number behave the same. Clean stone drains and stays loose. Minus stone, with fines included, compacts hard and holds water back.
- Mixing two different gravel sizes in one decorative area. The smaller stone works down between the larger pieces over time and the finished look gets muddy.
- Skipping a base layer under crushed stone or river rock. Without a compacted base underneath, even correctly sized stone will sink and spread unevenly.
- Reading a size number without checking the actual inch range on the listing. The same digit can mean different diameters between different grading systems, so the stated inches matter more than the number label.
- Choosing the smallest available size to save money on a driveway or parking area. Fine stone alone does not hold up to repeated vehicle weight the way a properly graded base and surface layer does.
Related Materials and Next Steps
Once you know the general size range you need, match it to a material family. Choose Pea Gravel for small, walkable, rounded stone, Crushed Stone for graded, angular stone that compacts for bases and driveways, and River Rock for larger decorative or drainage stone that will not compact. If you are still narrowing down crushed stone sizes for a specific job, start with the project itself, whether it is a base layer, a drainage line or a top-dress surface, and let that drive the diameter rather than picking a size first.
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Frequently Asked Questions
What is the smallest gravel size sold for landscaping?
Screenings or stone dust, which run under 1/8 inch, are the smallest material generally sold. They are used for leveling a base under pavers or filling joints rather than as a standalone surface. Pea gravel, at roughly 1/8 to 3/8 inch, is the smallest size typically used as a finished, walkable surface on its own.
What size gravel works best for a driveway?
Most driveways use crushed stone lets it lock together under vehicle weight, which is why it holds up better than smaller, rounded pea gravel in that setting.
What is the difference between crushed stone and gravel?
Crushed stone is mechanically broken from larger rock, so its pieces are angular with sharp faces that interlock and compact well. Gravel, in the strict sense, forms naturally through water and weathering, leaving rounded, smoother pieces. In everyday use both terms often get used loosely, so checking the shape and size on the listing matters more than the label.
What gravel size is used for drainage?
Drainage lines and French drains typically use clean, washed crushed stone in the 3/4 to 1.5 inch range. The larger, uniform size leaves open space between pieces so water moves through instead of pooling. Fines are screened out on purpose, since dust and small particles would otherwise clog those gaps over time.
Is pea gravel the same size as river rock?
No. Pea gravel is smaller, generally 1/8 to 3/8 inch, and river rock is chosen for larger accent stone and drainage work.
How do I pick the right gravel size for my project?
Start with the job rather than a size number. Walkways and play areas favor small, rounded pea gravel. Driveways and bases favor graded crushed stone that lets water pass. Decorative beds and dry creek beds favor river rock, sized to the scale of the space.
What does minus mean on a crushed stone size?
A minus label, such as 3/4 inch minus, means the stone includes pieces up to that diameter along with smaller fragments and fines rather than one uniform size. That mix is what lets it compact into a dense, stable base. A clean or washed version of the same size has the fines removed and stays loose instead of packing hard.
Can different gravel sizes be mixed in one area?
It is not recommended for a finished, visible surface, since smaller stone tends to settle down between larger pieces and the two sizes separate unevenly over time. Base layers are the exception, since a minus product is already a controlled blend of one size class plus fines, engineered to compact rather than stay loose like a decorative topping.