Gravel Sizes and Types: #57 Stone, #8, #3, Pea Gravel and More
#57 stone is a size number, not a kind of rock: in the AASHTO M43 list, all of it goes through a 1.5 in[1] sieve and between 0%[1] and 10%[1] of it goes through the No. 4 sieve, as FHWA prints the limits.
Estimates for planning, not professional advice. Read the full notice.
Work it out for your own sizes
Work out the #57 for your own areaExample to try: Length 20 ft, Width 10 ft, Depth 3 in
Gravel size numbers and their sieve limits
AASHTO M43 size numbers as FHWA prints them: the sieve all of the stone goes through, and the percent passing the No. 4 and No. 8 sieves
| Size number | All of it goes through this sieve | No. 4 sieve, percent passing: from | No. 4 sieve, percent passing: to | No. 8 sieve, percent passing: from | No. 8 sieve, percent passing: to |
|---|---|---|---|---|---|
| #57 | 1.5 in | 0% | 10% | 0% | 5% |
| #67 | 1 in | 0% | 10% | 0% | 5% |
| #68 | 1 in | 5% | 25% | 0% | 10% |
| #7 | 0.75 in | 0% | 15% | 0% | 5% |
| #78 | 0.75 in | 5% | 25% | 0% | 10% |
| #8 | 0.5 in | 10% | 30% | 0% | 10% |
| #89 | 0.5 in | 20% | 55% | 5% | 30% |
| #9 | 0.375 in | 85% | 100% | 10% | 40% |
Source: [1]
Limits as FHWA prints them in its table of selected designations. Only the sizes with both a No. 4 and a No. 8 limit are shown; the source prints more sieves, and none of these limits is a stone diameter.
Yards and tons of #57 for the example area
Cubic yards and tons of #57 stone for the example area, at each cited weight per loose cubic yard
| Source and material | Weight per loose cubic yard | Cubic yards | Tons |
|---|---|---|---|
| Penn State, AASHTO 57 stone | 1.5 ton/yd³ | 1.85 yd³ | 2.78 tons |
| Ohio DOT, gravel, size No. 4 and 57 | 2,500 lb/yd³ | 1.85 yd³ | 2.31 tons |
| Ohio DOT, limestone, size No. 4 and 57 | 2,400 lb/yd³ | 1.85 yd³ | 2.22 tons |
Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.
No weight for pea gravel or river rock is cited here: ask your supplier. Cubic yards are the area times the depth, before any waste allowance.
What the size numbers mean
The numbers come from the AASHTO M43 list, also printed as ASTM D448. FHWA counts 19 gradations[1] in it, each a size number with its own sieve limits, which is what the first table shows for the sizes that carry a No. 4 and a No. 8 limit.
In this study, 12 of the 19 AASHTO M43 gradations are tested and selected because of their common use in geotechnical applications ... The 12 unique samples ranged from an AASHTO No. 10 to an AASHTO No. 5.
Crushed stone and rounded gravel
A size number gives the sizes in the pile, not the material. Ohio DOT's conversion table lists both gravel and limestone as size No. 4 and 57: 2,500 lb/yd³[4] per loose cubic yard for gravel and 2,400 lb/yd³[4] for limestone.
The Department will measure the cubic yards of aggregate used loose in the vehicle at the point of delivery or calculate it by converting from weight using the following conversion factors: ... Gravel, Size No. 4 and 57 2500 lb/yd3 ... Limestone, Size No. 4 and 57 2400 lb/yd3
Shape is a separate word. Oregon State Extension calls pea gravel "rounded rock"; the sources opened for this page give no size number for pea gravel or river rock.
The University of New Hampshire has a rain garden that has been successful with a pea gravel layer on top of a layer of coarse sand. However, pea gravel (i.e. “rounded rock”) ...
Iowa State Extension lists river rock and pea gravel as separate entries, without a size for either.
Common inorganic mulches include: ... river rock ... lava rock ... pea gravel ... crushed brick ... limestone gravel ... caramel rock ... rubber chips ... woven landscape fabric ... plastic sheeting
Names vary by region and yard
Penn State's calculator lists AASHTO 57 stone under the Pennsylvania DOT name 2B, at 1.5 ton/yd³[2][3] per loose cubic yard. A yard may list the same stone by its number, by a local name or by a product name, so ask which size it is. The weight per yard chart sets the cited weights side by side.
Questions
What is 57 stone?
A size number from the AASHTO M43 list, not a kind of rock. The first table shows the sieve limits FHWA prints for #57 beside seven other size numbers.
What size is #57 stone?
FHWA prints sieve limits for it, not a single stone diameter: the first table gives the sieve all of it goes through and the percent passing the No. 4 and No. 8 sieves.
What are the types of gravel?
The sources opened here sort it three ways: by size number (the AASHTO M43 list), by material (Ohio DOT lists gravel and limestone in the same size) and by shape (Oregon State Extension calls pea gravel rounded rock).
Is pea gravel the same as river rock?
The sources opened do not say. Oregon State Extension calls pea gravel rounded rock, and Iowa State Extension lists river rock and pea gravel as separate entries among common inorganic mulches. Ask your supplier for the size range of each.
Calculate it for your project
Enter your own sizes to get the amount to buy or the layout figures, with the working shown and a page to print.
Try your own area in the gravel calculatorSources (6)
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Strength Characterization of Open-Graded Aggregates for Structural Backfills (FHWA-HRT-15-034), Chapter 3, Table 4 (opens in new tab), Federal Highway Administration, Turner-Fairbank Highway Research Center, June 2015; Table 4, Selected AASHTO M43-05 (ASTM D448) aggregate designations.
Code or government.
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 57 ... 1.5 inches 100 ... 1 inch 95-100 ... 0.50 inches 25-60 ... 4 0-10 ... 8 0-5”
“In this study, 12 of the 19 AASHTO M43 gradations are tested and selected because of their common use in geotechnical applications ... The 12 unique samples ranged from an AASHTO No. 10 to an AASHTO No. 5.”
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 67 ... 1 inch 100 ... 0.75 inches 90-100 ... 0.375 inches 20-55 ... 4 0-10 ... 8 0-5”
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 68 ... 1 inch 100 ... 0.75 inches 90-100 ... 0.375 inches 30-65 ... 4 5-25 ... 8 0-10”
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 7 ... 0.75 inches 100 ... 0.50 inches 90-100 ... 0.375 inches 40-70 ... 4 0-15 ... 8 0-5”
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 78 ... 0.75 inches 100 ... 0.50 inches 90-100 ... 0.375 inches 40-75 ... 4 5-25 ... 8 0-10”
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 8 ... 0.50 inches 100 ... 0.375 inches 85-100 ... 4 10-30 ... 8 0-10”
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 89 ... 0.50 inches 100 ... 0.375 inches 90-100 ... 4 20-55 ... 8 5-30”
“Table 4. Selected AASHTO M43-05 (ASTM D448) aggregate designations, percent passing through sieve: No. 9 ... 0.375 inches 100 ... 4 85-100 ... 8 10-40”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 1) -
DGLVR Materials Calculator, data file road-aggregate-fill-materials.xml (opens in new tab), Penn State Center for Dirt and Gravel Road Studies, data entry dated Monday, March 20, 2017 (value is in the calculator's data file, not in prose).
Code or government.
“Transcribed from the entry AASHTO 57 (PennDOT 2B) of the calculator's data file: 1.50 tons per cubic yard.”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 2) -
DGLVR Materials Calculator (opens in new tab), Penn State Center for Dirt and Gravel Road Studies, web page (page text, undated; calculator data dated March 20, 2017).
Code or government.
“the estimates generated will always appear as cubic yards of loose material and US tons as-shipped (loose) ... The volume to weight conversion factors used for the calculator are averages from across PA, based on observations by Center field staff.”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 3) -
Construction and Material Specifications, Item 410.06, Table 410.06-1 (opens in new tab), Ohio Department of Transportation, 2023 C&MS (January 1, 2023; online version 07/17/2026); the PDF prints the cubed unit as a replacement glyph, restored here as yd3.
Code or government.
“The Department will measure the cubic yards of aggregate used loose in the vehicle at the point of delivery or calculate it by converting from weight using the following conversion factors: ... Gravel, Size No. 4 and 57 2500 lb/yd3 ... Limestone, Size No. 4 and 57 2400 lb/yd3”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 4) -
Rain Gardens: Low-impact development fact sheet (EM 9207) (opens in new tab), Oregon State University Extension Service, published June 2018.
Code or government.
“The University of New Hampshire has a rain garden that has been successful with a pea gravel layer on top of a layer of coarse sand. However, pea gravel (i.e. “rounded rock”) ...”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 5) -
Using Mulch in the Garden (opens in new tab), Iowa State University Extension and Outreach (Yard and Garden), last reviewed February 2026.
Code or government.
“Common inorganic mulches include: ... river rock ... lava rock ... pea gravel ... crushed brick ... limestone gravel ... caramel rock ... rubber chips ... woven landscape fabric ... plastic sheeting”
Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used (Source 6)
These are summaries of what the sources say, not professional advice. Codes and product data change. Check with your building department and the product label about your own project.