#7 Stone: Size, Uses, Weight and How Many Tons

#7 stone is a clean crushed stone that tops out at about 1/2 inch and bottoms out near 3/16 inch, with almost no dust or sand mixed in. It sits between the familiar #57 and #8 sizes on the stone chart: smaller and smoother to walk on than #57, a bit chunkier than #8. Because the pieces are all roughly the same size and washed of fines, #7 drains freely and does not pack into a hard crust. Contractors use it as aggregate in concrete and asphalt, as cover stone for chip seal, for pipe bedding and for small drainage jobs, and homeowners use it for paths, paver bedding and decorative ground cover. A loose cubic yard weighs roughly 1.35 to 1.5 tons. This guide explains the size numbers, compares #7 with nearby stones, and shows how many tons to order.

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What “#7” means on the stone size chart

The number comes from ASTM D448, the standard size chart for coarse aggregate, and AASHTO M 43 uses the same size numbers for road work. Size No. 7 has a nominal range of 1/2 inch (12.5 mm) down to the No. 4 sieve (4.75 mm, about 3/16 inch). The standard limits how much of a sample, by weight, may pass each screen:

Screen opening	Share passing, by weight (size No. 7)
3/4 inch	100%
1/2 inch	90 to 100%
3/8 inch	40 to 70%
No. 4 (about 3/16 inch)	0 to 15%
No. 8 (about 3/32 inch)	0 to 5%

Read top to bottom: every piece fits through a 3/4-inch screen, nearly all of it fits through 1/2 inch, roughly half is larger than 3/8 inch, and very little is small enough to fall through the No. 4 or No. 8 screens. That tight band and the lack of fines are what make #7 an open, free-draining stone.

Not every quarry stocks a true #7. Some yards sell a “1/2-inch clean” or “half-inch chip” that is close to it, and some state transportation departments use their own size numbers. If a plan or a spec calls for size No. 7, ask the yard for the gradation sheet before you order.

#7 stone vs #57, #67 and #8

On the ASTM chart, a higher single number means smaller stone, and two-digit numbers such as 57 and 67 blend two sizes. Here is how #7 lines up with its neighbors:

Size	Nominal range	Fines?	Common uses
#57	1 in to 3/16 in	Very little	Drainage, concrete, driveway topping
#67	3/4 in to 3/16 in	Very little	Concrete, drainage, pipe bedding
#7	1/2 in to 3/16 in	Very little	Thin concrete and asphalt, chip seal, paths, pipe bedding
#8	3/8 in to about 3/32 in	Very little	Chip seal, paver bedding, pipe bedding
#9	3/16 in to about 3/64 in	Very little	Paver bedding chips, fine drainage

#7 vs #57. Both are clean, open stones that end at about 3/16 inch. The difference is the top size. #57 includes pieces up to an inch, which gives it more bulk for drainage trenches and driveway topping. #7 stops at 1/2 inch, so it looks finer, feels better underfoot and fits into thinner layers.

#7 vs #67. Think of #67 as #7 with a 3/4-inch top added. Concrete plants often pick between them based on how thick the pour is and how tightly the reinforcing steel is spaced; smaller stone flows into tight spots more easily.

#7 vs #8. #8 is the next size down and reaches a smaller bottom size. It is the more common choice for paver bedding and for many chip seals. #7 gives a slightly coarser texture and a bit more bulk per piece.

Common uses for #7 stone

Concrete aggregate for thinner pours. Smaller coarse aggregate suits thin slabs, toppings, and sections with closely spaced rebar. A ready-mix supplier or engineer chooses the mix, so ask before you substitute.
Asphalt mixes. Clean stone in this size range shows up in surface and leveling mixes. That is plant work, but it is why many asphalt producers stock it.
Chip seal cover stone. Stone around 1/2 inch is spread over hot liquid asphalt on rural roads and long driveways. See our chip seal driveway guide for how that surface works.
Pipe bedding and small drains. Clean, uniform stone packs evenly around pipe and lets water through. Local codes and pipe makers set the bedding rules.
Garden paths and ground cover. #7 is small enough to walk on comfortably and large enough not to track as badly as fine screenings. Use edging so it stays put.
Paver and flagstone bedding. Some installers use small clean chips like #7, #8 or #9 for the setting bed because they drain well. Follow the paver maker's instructions.

Where #7 stone is not the best choice

As a driveway base by itself. Clean stone has no fines to lock it together, so it shifts and ruts under tires. A base usually calls for a dense-graded material such as crusher run, with clean stone on top if you want it.
Large drainage trenches. #7 works, but bigger stone such as #57 moves more water per foot and costs about the same per ton. Our French drain gravel guide compares the options.
Steep slopes. Rounded or small clean stone can roll and migrate downhill. Larger angular stone or a binder holds better.
Play areas. Crushed stone has sharp edges. Playground surfacing has its own safety standards and products.

How much a yard of #7 stone weighs

Clean crushed stone has more air between the pieces than a dense base material, so it is a little lighter per yard. Most limestone, granite and trap rock in the #7 size weighs about 1.35 to 1.5 tons per loose cubic yard, about 2,700 to 3,000 pounds. We use 1.4 tons per yard below. Heavier rock types and damp stone weigh more, and yards that sell by the scoop rather than by the scale ticket may load a little more or less. Our crushed stone weight chart covers other materials.

How deep to lay #7 stone

Walkway or garden path: about 2 to 3 inches over landscape fabric, or over a compacted base on soft ground.
Decorative ground cover: about 2 inches is often enough to hide the soil.
Paver bedding: usually about 1 inch, screeded flat over the base.
Driveway topping: about 2 inches over a compacted base, though larger stone holds up better to tires.

Treat these as starting points. A product installation guide, permit or engineer's drawing comes first.

How many tons of #7 stone to order

Measure length and width in feet and depth in inches, then:

Cubic yards = length × width × depth in inches ÷ 324
Tons ≈ cubic yards × 1.4
Square feet covered per ton ≈ 230 ÷ depth in inches

Add 5 to 10 percent for uneven ground and stone that settles into the soil or base. Clean stone does not compact as much as screenings, but some always disappears.

Depth	Approx. area per ton	Tons per 100 sq ft
1 inch	about 230 sq ft	about 0.43
2 inches	about 115 sq ft	about 0.86
3 inches	about 77 sq ft	about 1.3
4 inches	about 58 sq ft	about 1.7

Example: a 4-foot by 40-foot path, 3 inches deep. 4 × 40 × 3 ÷ 324 = about 1.5 cubic yards. 1.5 × 1.4 = about 2.1 tons. With 10 percent added, plan on about 2.3 tons.

Example: a 12-foot by 12-foot patio bedding layer, 1 inch deep. 12 × 12 × 1 ÷ 324 = about 0.44 cubic yards, or about 0.6 tons. With a little extra, about 0.7 tons of #7 stone covers the bedding, plus whatever base stone goes underneath.

For bigger jobs, our crushed stone coverage guide and the base calculator do the math for you.

Buying tips

Ask for it by size and by description. If a yard does not list #7, ask for “1/2-inch clean stone” and check the gradation.
Ask what rock it is. Limestone, granite, trap rock and gravel all come in this size and differ in color, weight and hardness.
Check the minimum load. Many yards have a delivery minimum, and a small job may be cheaper to pick up in a trailer or pickup if your vehicle can carry the weight.
Pick a dump spot. Have the truck drop the stone close to where you will spread it, on a tarp or a hard surface, and away from septic lines.

Questions people ask

What size is #7 stone?

ASTM size No. 7 runs from 1/2 inch down to the No. 4 sieve, about 3/16 inch. All of it passes a 3/4-inch screen, 90 to 100 percent passes 1/2 inch, 40 to 70 percent passes 3/8 inch, and no more than 15 percent passes No. 4.

What is #7 stone used for?

It is used as coarse aggregate in thinner concrete pours and asphalt mixes, as chip seal cover stone, for pipe bedding and small drains, and for garden paths, ground cover and paver bedding.

Is #7 stone the same as #57 stone?

No. Both end at about 3/16 inch and have very little dust, but #57 includes stone up to 1 inch while #7 tops out at 1/2 inch. #7 looks finer and suits thinner layers.

How much does a yard of #7 stone weigh?

About 1.35 to 1.5 tons per loose cubic yard, roughly 2,700 to 3,000 pounds, depending on the rock type and moisture. Use 1.4 tons per yard for planning.

Does #7 stone compact?

Not much. It is a clean stone with almost no fines, so it settles and locks a little when tamped but does not form a hard crust the way crusher run or screenings do.

How many square feet does a ton of #7 stone cover?

About 230 square feet at 1 inch deep, 115 square feet at 2 inches and 77 square feet at 3 inches. Add 5 to 10 percent for settling and uneven ground.

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