Gravel · Reference Chart
Gravel size chart
Every standard aggregate size number — #1 through #10, the graded blends, crusher run, pea gravel and river rock — with dimension ranges and the jobs each size is made for, per ASTM D448 and AASHTO M 43.
The gravel size chart
Size numbers per ASTM D448 / AASHTO M 43. Each range runs from the sieve nearly all particles pass down to the sieve nearly all are retained on.
| Size / name | Particle range | Typical uses |
|---|---|---|
| #1 | 1.5–3.5 in (37.5–90 mm) | Culvert bedding, stabilizing very soft ground, erosion controlToo large to shovel or rake — machine-placed |
| #2 | 1.5–2.5 in (37.5–63 mm) | Railroad ballast, construction entrances, mud control |
| #3 | 1–2 in (25–50 mm) | Drainage beds, dry wells, first lift of a driveway base |
| #357 | 2 in–No. 4 (50–4.75 mm) | Thick base lifts, pipe backfill, subgrade stabilizationGraded blend spanning sizes #3 through #7 |
| #5 | 1/2–1 in (12.5–25 mm) | Road base topping, filter stone around structures |
| #57 | 1 in–No. 4 (25–4.75 mm) | Concrete aggregate, driveway topping, French drains, pipe beddingThe most-ordered size in North America |
| #67 | 3/4 in–No. 4 (19–4.75 mm) | Concrete mixes, pipe bedding, slightly tighter finish than #57 |
| #8 | 3/8 in–No. 8 (9.5–2.36 mm) | Chip seal, asphalt mixes, walkway topping over a base |
| #89 | 3/8 in–No. 16 (9.5–1.18 mm) | Paver joint filling, permeable paving reservoirs, decorative topping |
| #10 | No. 4 to dust (< 4.75 mm) | Screenings: paver leveling beds, path binder, fill under slabsAlso sold as stone dust or manufactured sand |
| Crusher run | 3/4 or 1.5 in "minus" — stone down to dust | Compactable base for driveways, patios and shedsRegional names: CR-6, 21A/21B, DGA, road base |
| Pea gravel | 1/4–5/8 in (6–16 mm), rounded | Walkways, playgrounds, dog runs, mulch alternativeA commercial name, not an ASTM size number |
| River rock | 1–3 in (25–75 mm), rounded | Dry creek beds, borders, decorative ground coverScreened natural stone; larger cobbles also sold |
Weights for these sizes live in the density database, and the crushed-stone cluster has a deeper guide to each size if you want more than one line per number.
How to read aggregate size numbers
The system dates to early highway specifications and reads backwards from intuition: the smaller the number, the larger the stone. #1 is fist-sized rock; #10 is dust. Single-digit numbers are close to one particle size; multi-digit designations are graded blends named by the sizes they span — #57 covers the #5-to-#7 band, #89 the #8-to-#9 band, and #357 runs all the way from #3 down to #7.
Matching size to the job
Six decisions that cover most residential orders.
| Job | Best size | Why it works |
|---|---|---|
| French drain | #57, washed | Open voids move water; no fines to clog the fabric |
| Driveway base | Crusher run (or #3 first lift) | Fines lock under compaction into a near-solid layer |
| Driveway surface | #57 | Big enough to stay put, small enough to drive on |
| Paver joints & bedding | #89 joints, #10 bedding | Fine chip sweeps into joints; screenings screed flat |
| Walkway or patio surface | Pea gravel or #8 | Comfortable underfoot; contain with edging |
| Muddy site entrance | #2 or #3 | Large stone bridges soft ground and sheds mud |
Size chart questions
- What size is #57 gravel?
- #57 stone is graded from 1 inch down to the No. 4 sieve (25 to 4.75 mm) — most particles are about 3/4 inch. It is the default order for concrete aggregate, driveway topping and French drains, and if a supplier just says 'gravel', #57 is usually what arrives.
- Do smaller size numbers mean smaller stone?
- The opposite: under ASTM D448 the numbering runs from #1 (up to 3.5 inches) down to #10 (screenings passing 4.75 mm). Multi-digit designations like #57, #67, #89 and #357 are graded blends spanning the sizes their digits reference — #57 covers the #5-to-#7 range.
- What is the best gravel size for a driveway?
- Use two sizes: a compacted crusher-run base (its fines lock into a near-solid layer), topped with 2–3 inches of #57 for the running surface. Skipping the base and laying #57 straight on soil is the classic mistake — clean stone migrates and ruts without a locked base under it.
- Are ASTM D448 and AASHTO M 43 sizes the same?
- Effectively yes — the two standards use the same size numbers and gradation bands. ASTM D448 is the general classification; AASHTO M 43 adopts it for road and bridge work, which is why a DOT spec and a landscape yard both understand '#57' identically.
- Is pea gravel an official ASTM size?
- No. Pea gravel is a commercial name for rounded natural stone screened to roughly 1/4–5/8 inch. Its nearest ASTM cousin by particle size is #8, but #8 is crushed and angular — the two behave very differently underfoot and are not interchangeable in drainage or paving specs.
- What size gravel drains best?
- Clean, washed single-size stone in the #57 range drains best for most work: its voids stay open because there are no fines to plug them. Go larger (#3) for dry wells and high-flow beds. Never use crusher run or screenings where drainage matters — the fines seal the layer.
Sized the stone? Now size the order
Enter your dimensions and gravel type — the calculator returns cubic yards and tons.
Related references & guides
Sources & references
- [1]ASTM D448: Standard Classification for Sizes of Aggregate — ASTM International, 2017
- [2]AASHTO M 43: Sizes of Aggregate for Road and Bridge Construction — AASHTO, 2018
- [3]The Aggregates Handbook, 2nd ed. — National Stone, Sand & Gravel Association, 2013