No. 57 Stone: Uses, Sizing & How Much You Need

If you’re not sure whether No. 57 stone is right for your project, you’re in good company. You’re standing at the quarry yard, a supplier waiting on the other end of the counter, and you’ve just been asked: “What size are you looking for?” You heard it mentioned somewhere online, but you’re not sure if it’s the right call for what you’re building. That uncertainty is exactly where mistakes happen, and they usually show up as a French drain that doesn’t drain or a driveway that turns into a muddy mess after the first hard rain.

No. 57 stone is one of the most widely specified aggregates in residential and light commercial construction. It shows up in driveways, French drains, concrete mixes, foundation drainage systems, and septic leach fields. Its popularity isn’t accidental: the stone’s physical properties make it genuinely useful across a wide range of applications. This guide covers what it actually is by spec, where it performs best, how to choose between washed and unwashed, and how to estimate the tonnage before you pick up the phone.

What No. 57 stone actually is

The official gradation in plain English

No. 57 stone is a standard ASTM and AASHTO size classification for crushed stone, not a brand name: it usually consists of particles mostly between 3/4 inch and 1.5 inches, with very little fine material, so it acts as a clean, open-graded aggregate with strong drainage. If you’re a homeowner, contractor, landscaper, or outdoor project planner trying to estimate stone for a driveway, drainage run, patio base, or concrete support layer, this guide explains what No. 57 stone is, where it works best, how washed and unwashed versions differ, and how to estimate quantity, weight, and likely cost using the Crushed Stone Calculator.

That matters because the stone size and fines content you choose directly affect water flow, compaction, structural performance, appearance, and how much material you should order. No. 57 is commonly used for French drains, backfill, driveway top layers, concrete mixes, and walkways because it balances load support with fast drainage, and in visible applications it can also add a clean, beautiful aesthetic. By the end, you should be able to tell whether No. 57 is the right material for your project and order a realistic amount without relying on guesswork.

No. 57 is not a brand name or a quarry-specific product. It’s a size classification defined under ASTM D448 and AASHTO M43, which means every supplier using that designation is working from the same sieve gradation. Most particles fall between 3/4 inch and 1.5 inches, with 95 to 100 percent passing a 1-inch sieve and 0 to 10 percent passing the No. 4 sieve (4.75 mm) per ASTM D448 / AASHTO M43. This stone size classification sits within a broader system of crushed stone grades and gravel sizes used for different jobs. That last number is the one that matters most for how this stone behaves on the job.

The full sieve breakdown looks like this:

Sieve Size	Percent Passing
1 1/2 in.	100%
1 in.	95-100%
1/2 in.	25-60%
No. 4 sieve	0-10%
No. 8 sieve	0-5%

That near-zero fines content is what separates this stone from dense-grade options. Produced by crushing natural rock deposits such as granite, limestone, or quartzite into smaller pieces, No. 57 is a clean aggregate, often called clean stone because the fine byproduct removed from it is stone dust, leaving the open-graded mix with very little material to fill voids. While No. 57 is technically produced as a blend of nearby sizes per AASHTO M43 / ASTM D448 practice, it behaves as a nominally open-graded aggregate, particles are roughly uniform in size, which creates significant void space and gives it the drainage characteristics needed for different types of drainage applications; that same cleaner gradation also helps it maintain a crisp look for decorative driveways and walkways with a beautiful aesthetic. For reference to the official tables and gradation, see the AASHTO 57 stone specs.

What “open-graded” means for your project

Because there is almost no dust or fine material, No. 57 is generally suitable when you need water to move through the layer, not when you need a dense, compacted surface, because the stones stack on top of each other without filling the gaps between them. Those gaps help water drain naturally and are what make the material useful in drainage applications and other drainage solutions. Compare that to crusher run, a dense-graded mix that includes everything from 3/4-inch stone down to fine dust. Crusher run compacts into a firm surface; No. 57 stone stays loose and permeable, so proper installation is needed to achieve the intended result. Both have a role, but they are not interchangeable, and choosing the correct stone size is essential to complete the project successfully.

Why drainage solutions are where No. 57 stone earns its reputation

How void space moves water

Open-graded particles create substantial void space, commonly reported in geotechnical practice as a significant portion of total volume compared with dense-graded materials. When water enters that stone layer, it has a clear, unobstructed path to travel downward and away from the structure, and the irregular shape of the individual stones also helps them interlock while still leaving open paths for flow. There is no fine material to absorb it, slow it, or hold it near the surface. That physics makes this aggregate the standard choice for retaining wall backfill, where it helps relieve hydrostatic pressure by letting water escape behind the wall, as well as under slabs on wet sites and in any trench designed to move water away from a foundation or yard.

The drainage capacity doesn’t just perform on day one. As long as the stone is protected with filter fabric and the surrounding soil doesn’t migrate into the voids, the permeability stays high for years. That long-term performance is why engineers and contractors continue specifying it over cheaper alternatives, since it improves drainage around structures, supports structural integrity, and reduces erosion pressure in wet areas.

Where it fits in a layered drainage system

In a typical residential French drain, the cross-section follows a consistent sequence: a trench lined with geotextile filter fabric, a perforated pipe laid at the bottom (with perforations oriented to encourage inflow, commonly downward-facing in many installations), and No. 57 stone used for bedding and backfill around drainage pipes before the fabric is folded over the top and the trench is backfilled. The stone’s job is to move water quickly toward the pipe while the fabric keeps soil out of the voids. Pull the fabric out of that equation and the stone clogs over time; swap the aggregate for a dense-grade material and the drainage capacity drops immediately. For detailed sizing and installation guidance, see the French Drain Gravel: Right Type, Size & How Much to Order guide.

The same principle applies to foundation drain systems and septic leach fields. In utility and construction work, it is also used for lining underground pipes and cables because the stone supports flow around the line. The stone provides the void space that allows water to infiltrate or flow, and the uniform particle size ensures those voids stay consistent throughout the bed. The aggregate choice is the reason these systems and other drainage projects either perform well for decades or fail within a few years.

Washed vs. unwashed No. 57 stone: which fits your project

What the washing process actually removes

Washed No. 57 stone went through a rinse process at the plant that stripped off the crusher dust and residual fines. What comes off the conveyor is clean stone, commonly called clean stone because washing removes fine dust, with fully open voids. Unwashed material still carries a coating of fine particles from the crushing process. Both are classified as open-graded aggregate, and neither compacts into a smooth, dense base the way crusher run does. The difference in fines content, however, changes how each one performs under specific conditions.

For long-term drainage, washed stone is clearly the better choice. The voids stay open because there is nothing left to migrate into them over time. Unwashed stone starts with partially filled voids, and during transport or handling those fines can become more noticeable in the pile; as they settle and surrounding soil works its way in, drainage capacity slowly decreases. That degradation may take years, but it is why engineers specify washed material for any application where drainage is the primary function.

Matching the option to the job

Washed No. 57 stone is the right call for French drains, foundation drainage, and septic leach fields because it stays a clean aggregate with open voids for long-term drainage work. Any time you need sustained, long-term drainage, the cleaner stone wins, which also makes it useful across residential and commercial projects. Unwashed gives slightly more initial stability, which can be useful under utility trench backfill, wall backfill, or as a base layer where a modest lock-up is acceptable and drainage is secondary. If drainage comes first, choose washed. If you need a bit more stability in a base application, unwashed works and typically costs a little less.

The best uses for No. 57 stone

Driveways and parking pads

No. 57 crushed stone is a reliable driveway material for one main reason: the angular edges interlock under vehicle weight, and that angular shape gives driveways better traction, stability, and a beautiful aesthetic for driveways and walkways. Rounded gravel like pea stone rolls and displaces; angular No. 57 locks together and holds its position. It also sheds water instead of trapping it near the surface, which helps in drainage layers and permeable pavement and prevents the frost heave and soft spots that plague driveways built on poorly drained subgrade. For a broader comparison of driveway aggregates and layers, see the Best gravel for driveways: Types, Layers, and Costs Guide.

For a light residential driveway on stable ground, many contractors use several inches of aggregate base, with thicker layers needed for soft soil, wet areas, or heavier traffic. On soft or wet subgrade, that thickness still depends on site conditions, and laying geotextile fabric between the subgrade and the stone helps prevent mixing at the sub base. Note that local conditions and any applicable specifications may require different depths, always confirm with your contractor or local DOT guidance. The stone is extremely common for driveways, one of its common uses is as a base layer for parking areas and asphalt roads, and it also works under asphalt paving because the compacted base supports the pavement above while tar and other aggregates bind the surface; it is recognized for durable, long-term service.

French drains and foundation drainage

This is the application where No. 57 stone is almost universally specified. A residential French drain commonly runs 12 to 18 inches deep, with the perforated pipe sitting in the bottom 4 to 6 inches and the stone filling the trench above it to within a few inches of grade, though required dimensions vary with site conditions and design.

The same free-draining material is also used in landscaping projects such as dry creek beds, where you want water directed through stone rather than soil for drainage-focused landscaping.

For a 50-foot drain trench that is 12 inches wide and 12 inches deep, you’re looking at roughly 2 to 3 tons of stone depending on trench geometry. That number adds up quickly, and estimating short means a second delivery charge at exactly the point in the project when you don’t have time to wait.

Concrete aggregate and base layers

No. 57 stone is a standard coarse aggregate in ready-mix concrete and other concrete mixes. When a ready-mix plant specifies 3/4-inch coarse aggregate, they are typically referring to this size range. Contractors also use it as a sub base under slabs and other concrete flatwork because it provides a stable platform while still allowing moisture that wicks up from the subgrade to drain away rather than accumulate. Pouring a slab directly over compacted soil with no drainage layer leaves moisture with nowhere to go. A 4-inch bed of No. 57 stone under the slab solves that problem without adding significant cost and creates a stable working layer below flatwork.

For additional perspective on common applications and installation uses, see this overview of the uses of No. 57 limestone.

Estimating how much No. 57 stone you need

Coverage math at common depths

The core numbers are straightforward. At a 2-inch depth, one ton covers roughly 100 square feet. At 4 inches, that drops to about 50 square feet per ton. At 6 inches, plan for approximately 33 square feet per ton. These figures are based on a bulk density of approximately 1.45 tons per cubic yard, which is a standard estimating value for crushed limestone including No. 57 size. Granite runs slightly heavier at approximately 1.50 tons per cubic yard — adjust accordingly if your supplier sources from granite quarries. Actual density can vary ±10% by stone source, gradation, and moisture content.

Here’s a quick example. A French drain trench that is 12 inches wide, 12 inches deep, and 50 feet long holds about 50 cubic feet of stone. Divide by 27 to get cubic yards: that’s roughly 1.85 cubic yards. Multiply by 1.45 tons per cubic yard (standard limestone estimating density) and you need about 2.68 tons for the stone fill alone, before any waste factor. Add 10 percent for spillage, irregular trench walls, and compaction, and your order should be at least 3 tons.

Running that math before you call the supplier keeps you from guessing at the yard and ordering short. If you want a quick refresher on nominal sizes, read our guide on what size is 57 stone.

Using Crushed Stone Calculator to lock in your number before you order

Ordering short means paying a second delivery charge, which can easily add $100 or more to a small job. Ordering heavy means storing stone you don’t need until you find another use for it. Neither outcome is acceptable when the math is simple to run ahead of time.

For more details, check out our Crushed Stone Guides, or use the Crushed Stone Calculator to enter your project dimensions and select a granite or limestone density preset before ordering. The tool returns your volume in cubic yards alongside an estimated tonnage, so you can compare that number with your supplier’s quote. You can also add a waste factor, such as 5% or 10%, to account for spillage, irregular terrain, uneven trench walls, and material loss. Run the calculator before you call your aggregate supplier, not while you’re standing in the lot trying to do the math in your head. If you prefer an alternate calculator, the cubic yard/ton calculator is another quick option, and running the numbers first helps complete the order more accurately while saving time.

What No. 57 stone costs per ton in 2026

The price range you should expect

In 2026, No. 57 stone at the yard typically runs $45 to $75 per ton for the material itself, with quarry and bulk pricing often toward the lower end of that range and retail or landscape suppliers pushing higher. Delivered pricing on smaller orders commonly lands between $75 and $150 per ton equivalent once trucking is factored in. Limestone-source quarries in the Midwest and South tend to come in at the lower end. Markets farther from aggregate sources, or in higher-cost metro areas, will push toward the top. Prices vary by region, so confirm current rates with your local supplier.

What moves the number up or down

Three factors control the price more than anything else: proximity to a quarry, order size, and whether you pick up or take delivery. A full truckload often receives the best per-ton pricing, though truck capacities vary and loads commonly fall in the range of 18 to 22 tons depending on truck type and region. Half-loads and small-quantity deliveries can push the effective cost much higher once trucking is included. If your project lands near a full truckload, ask the supplier whether rounding up would reduce the effective delivered cost per ton. The extra stone may cost less than a second delivery charge, but only order more if you have a realistic use or storage space for the leftover material.

The bottom line on No. 57 stone

No. 57 stone is a 3/4-inch to 1.5-inch open-graded aggregate built for drainage, durable enough for driveways, and versatile enough to work as a concrete base or French drain fill. Washed is the right call for any application where sustained drainage is the goal. Unwashed is acceptable for base layers where a little more stability helps and drainage is secondary. Cost runs $45 to $75 per ton at the yard in 2026, with delivery adding significantly to smaller orders.

Before placing any order, run your dimensions through the Crushed Stone Calculator using the granite or limestone preset. The tool handles the cubic yard to tonnage conversion automatically and lets you include a waste factor if needed, giving you a number you can review with your supplier. Measure your area, plug it in, and you’ll have a quantity you can confirm with confidence before you commit to the order.