Tools · No. 06Driveway, walkway, French drain, decorative

Gravel calculator — yards, tons, and the compaction cushion.

Put in length, width, and the depth you want delivered. The calculator returns cubic yards andtons, because suppliers quote one or the other and the conversion changes with the type of gravel. For driveway base, it also adds the compaction cushion that crusher run needs so you don't end up an inch short after the plate compactor goes over it.

Most home gravel jobs are one of five things: driveway base, driveway top dressing, a walkway, a yard French drain, or a decorative bed. The right stone for each is different — angular crusher run for compactable base, clean #57 for drainage, pea gravel for walkways, river rock for beds. Pick the use case above the form and the type defaults follow.

Before you call the gravel yard7 things to have ready

Length and width of the area (feet)
Finished depth goal (inches)
Will the material be compacted? — adds a loose-depth cushion for crusher run / road base
Loose order depth (what you actually type in)
Use case: driveway, walkway, drain, decorative
Gravel type (or pick it from the chooser below)
Does the supplier sell by ton or cubic yard?
Delivery minimum + truck access at your house

Driveway subbase — compactableMode · 4-6″ compacted base (order LOOSE × 1.20)

Gravel type

Exact · 8.89 yd³

Tons · 15.14

Type · Crusher run (compactable)

Compaction note · Crusher run loses 15-20% volume between loose and compacted. The depth above is what the supplier delivers — multiply your design depth by 1.20 to get the order depth.

Material order cushion

The math8.89 yd³— 480 sq ft × (6″/12) / 27 = 8.89 yd³

What I’d actually order9.75 yd³or 15.14 tons at the dispatcher

Why the cushionGravel loses a fraction in transit (settling on the truck, spillage at the chute), spread inefficiency at corners and edges, and weight tolerance at the supplier (a 5-yard ticket may show up at 4.85). The cushion absorbs all three so the spread depth lands where you measured.

When NOT to over-orderDon't double-cushion. The 7% default already covers settle-in-transit, corner spillage, and supplier tolerance — adding another 5% on top means a pile of leftover gravel hardening on your driveway. If the project is genuinely uncertain, schedule a second smaller delivery rather than over-ordering once.

Why the calc asks for loose depthCrusher run loses ~17.5% to compaction

As deliveredWhat you order

5″ loose — what the truck dumps

After compactionDesign depth

4″ finished — what the driveway feels like

Crusher run, road base, and any compactable mix lose 15-20% of their height when a plate compactor passes over them. The calculator above asks for loose depth— the number the supplier weighs and dumps. To land at a 4″ compacted base, enter about 5″ loose. The compactable types (crusher run / road base) are the only ones this applies to; #57 clean, pea gravel, and decorative river rock stay loose and don't shrink.

Quick tipsWhat I'd want you to know in 60 seconds

Crusher run for the base, #57 for the top. Compactable fines lock the subbase; angular clean stone stays loose for drainage.
Order LOOSE depth × 1.20 for any compactable layer. Crusher run loses 15-20% volume in compaction — design 4 inches, order 5.
Use geotextile fabric under any gravel driveway on clay. Without it, fines from the soil migrate up into the gravel within a few seasons and you're back to mud.
Pea gravel is for walkways and decorative beds, not driveways. Tires shove it into ruts within a season.
Confirm yards AND tons when you call dispatch. Suppliers bill by the ton; the cubic-yard ticket and the per-ton invoice should agree at the density of the gravel you ordered.
Ask the dispatcher about the delivery minimum before you commit. Many aggregate yards run a 3-5 yd or ton-equivalent minimum, and the number varies by region, material, and truck. When the math is under their floor, bagged from a big-box at 0.5 cu ft per bag is the call.

Worked example12×40 driveway, moderate-soil two-layer build

A 12×40 residential driveway, two layers, 8 inches compacted at finish.

480 square feet of driveway. Base layer: 7 inches loose crusher run — lands at roughly 6 inches compacted, the upper end of the 4-6″ subbase range for moderate soil. Volume math: 480 × (7/12) / 27 = 10.37 cubic yards exact, or 16.10 tons at the 115 lb/ft³ density. Add the 7% cushion and the practical order is 11.25 yards — about 17.47 tons. I'd call Vulcan or a regional Chicago-metro yard and ask for 17.5 tons loose to leave a working cushion, with delivery confirmed for the morning so I have all day to spread and compact before any weather.

Top dressing: 2 inches of #57 angular stone over the compacted base. Volume math: 480 × (2/12) / 27 = 2.96 cubic yards exact at 100 lb/ft³ → about 4.0 tons. Add cushion → 3.25 yards or 4.39 tons practical — a separate delivery, but a smaller one. Total at finish: about 6 inches compacted base + 2 inches top dressing = 8 inches, the lower end of the FAQ's 8-12 inch driveway range. Heavier clay or higher traffic moves you to the three-layer spec (thicker subbase plus a middle layer of #3 stone bridging to the top) — same math, a third truck. Geotextile fabric goes down BEFORE the base. On heavy Chicago-suburb clay, skipping that fabric is the single biggest reason gravel driveways turn back into mud strips by year three.

What gravel type should I pick?

Before the calculator gives you a useful tons number, you have to know which stone you're ordering. The four most common types for residential jobs:

Drainage / French drain#57 clean stone, ¾″Angular, no fines — water flows through. Don't pick this for a driveway top dressing if your supplier doesn't compact the base first.

Compacted driveway baseCrusher run / road baseFines + ¾″ angular pieces. Compacts into a load-bearing layer. The only type the calc applies a compaction cushion to.

Walkway / decorativePea gravel, ¼-⅜″Rounded, soft underfoot. Do not use as a driveway top — tires shove it into ruts within a season.

Bed / accent stoneDecorative river rockLarger rounded stones, picked for color. Not structural. Edge restraint matters more than depth.

Picking the wrong stone is the most common gravel mistake. Crusher run on a French drain clogs within a few seasons. Pea gravel on a driveway gets shoved into ruts. The use-case tabs on the calculator above set the type for you — change it only if you have a specific reason.

Yards vs tons — what do I ask the supplier for?

The calculator shows both. Pick whichever number your supplier uses, but confirm the conversion before the truck rolls.

Aggregate yards (Vulcan, Lehigh, regional quarries): usually bill by the ton at the scale on the way out. Cubic yards is what you measured; tons is what they invoice.
Landscape suppliers: more often quote by the cubic yard — the math is simpler at retail and the bag equivalents are tied to volume, not weight.
The conversion changes with the stone. A cubic yard of crusher run weighs about 1.55 tons; a cubic yard of pea gravel weighs about 1.30. Same volume, different ticket. See how much a yard of gravel weighs for the per-type breakdown.
Wet loads run heavier. Same gravel, same yard count, more weight on the scale. Ask the dispatcher whether the published density assumes dry or moist material if the order is big enough that a few percent matters.
Ask for both on the dispatch ticket.The calculator's yards × per-type density should land within a few percent of the supplier's tons number. If they don't agree, somebody's using a different density — sort it out before delivery.

Worked example — a 12 × 40 driveway from a Chicago-suburb rehab

The calculator runs the math instantly, but it helps to see the four steps once. A typical driveway base order, walked through:

Measure the area in feet.Long edge × short edge. For an L, a curve, or a trapezoid, split into rectangles, compute each, and sum. Don't eyeball — a 10% measurement error blows the cushion. The example driveway is 12 ft × 40 ft = 480 sq ft.
Pick the spread depth. Driveways take 8-12 inches total in three layers (compacted crusher-run subbase + #3 middle + 2″ #57 top). Walkways: 2-3″. Yard French drain trench: 12″. Decorative bed: 2-3″. The example uses 6″ for a single-layer base replacement.
Compute cubic yards. Area × depth (in feet) ÷ 27. Depth in inches divides by 12 first. So 480 × (6 ÷ 12) ÷ 27 = 480 × 0.5 ÷ 27 = 8.89 yd³. That's the exact volume before any cushion.
Add the cushion, then round to the dispatch unit. Multiply by 1.07 for the 7% cushion: 8.89 × 1.07 = 9.51 yd³. Round up to the next quarter-yard the supplier honors: 9.75 yd³. For crusher run at 115 lb/ft³, that's 9.75 × 27 × 115 ÷ 2000 = 15.14 tons. Call the supplier with both numbers and confirm they agree on type and quantity before the truck rolls.

That's the math the calculator runs above. The four-step version exists so you can sanity-check a quote a contractor handed you, or run the numbers on a job site without a phone.

Where gravel orders go wrong

The pattern of failed gravel jobs is narrow. Most of them trace back to one of these:

Entering finished depth into a calculator that wants loose depth. A 4″ compacted crusher-run base needs about 5″ ordered loose. If you enter 4″ for crusher run, you land at roughly 3.3″ after compaction — and the driveway feels soft the first time a delivery truck rolls in.
Crusher run on a French drain. The fines clog the void space within a few seasons and the drain stops draining. French drains want clean angular stone (#57), not fines-heavy compactable mix.
Pea gravel on a driveway. Rounded shape = tires push it into ruts. Pea gravel is for walkways and decorative beds. Driveways get crusher-run base + (optionally) an angular top.
Forgetting the supplier minimum. Many aggregate yards have a 3-5 yd or ton-equivalent delivery minimum, and charge a small-load fee ($75-$150 typical) below it. Numbers vary by region, material, and truck — ask the dispatcher when you call. If the math says 1.5 yards, switch to bagged from a big-box (0.5 cu ft per bag) or call a landscape yard instead of an aggregate quarry.
Skipping geotextile fabric over soft clay.Without fabric under a driveway, soil fines migrate up into the gravel within a few rainy seasons and you're back to mud. Same story for a French drain — the trench needs fabric wrapped around the stone column.
Ordering the exact math with no cushion.Transit settle, corner spillage, and supplier weight tolerance (a 5-ton ticket might show up at 4.85) all eat into the number. The 7% practical-order cushion above absorbs that; don't override it to zero.
Assuming every supplier's “ton per yard” is the same. Densities published on spec sheets are midpoints. Wet crusher run can run 125 lb/ft³ at one yard and 115 lb/ft³ at the next. For big orders, ask for the published density.

When this calculator is enough — and when to call someone

This is an ordering calculator, not a drainage or structural designer. The volume math is honest; the use-case decision is honest. The cases it covers cleanly:

Driveway top dressing over an existing compacted base.
Walkway stone — pea gravel or crushed stone path.
Decorative bed stone around foundation plantings or yard accents.
Simple shallow yard or surface French drain catching downspout discharge or pooling runoff away from the house.
A modest residential driveway base on reasonable soil, where compaction in 2″ lifts will land at the design depth.

Call a contractor, drainage pro, or structural engineer when:

Water is entering a basement, slab, or crawl space. A surface French drain catches what runs over the lawn. It does not solve water that's already at footing depth — that's a waterproofing scope (footing drains, sump system, exterior membrane).
The driveway subgrade is soft clay, recent fill, or ruts under foot. No depth of gravel fixes a subgrade that won't support a truck. Excavation, compaction, or stabilization belongs on the project plan first.
You're not sure where the water goes.A drain that dumps into the neighbor's yard, into a window well, or onto the same wet spot you're trying to fix is worse than no drain. Outlet location is the first question to answer.
Slabs, retaining walls, frost-depth footings, or structural fill are involved. Base prep for anything load-bearing is geotechnical territory. The volume math here is the same, but the spec is somebody else's.
The work touches the public right-of-way, a culvert, or stormwater rules. Driveway aprons at the curb, culvert pipes under driveways, and any disturbance in the municipal ROW typically need a permit and an engineered section — not a homeowner ordering calc.

From the field

On a yard or surface French drain — the common DIY scope, catching downspout discharge or surface runoff before it pools at the foundation — the trench dimensions are tight enough that the math is easy. A 30-foot run at 12″ deep × 12″ wide is 1.11 yards exact, 1.25 yards practical, about 1.69 tons. That's usually below an aggregate yard's delivery minimum (often 3-5 yards or a ton equivalent — call to confirm), so it goes to a landscape yard or pays a small-load surcharge. Stone choice matters more than most installers admit: #57 angular clean stone stays loose for flow; crusher run clogs within a few seasons because the fines pack the void space. Below-grade foundation perimeter drains run at footing depth (3-8 ft typical) and belong to a waterproofing contractor — not this calculator.

Methodology

Every number on this page traces to one of three layers — site arithmetic for the volume math, supplier spec sheets for per-type bulk densities (cross-checked against Omnicalculator and InchCalculator industry references), and USDA NRCS aggregate-surfacing standards for the driveway depth + geotextile guidance. The per-calculator sourcing tier in methodology spells out which sources back which kinds of claims. For the step-by-step volume walkthrough on any job, see how much gravel do I need; for the reverse direction when the supplier ticket is in tons, see how much is a ton of gravel.

Show the formulas

Volume: (L ft × W ft × T″ / 12) / 27 = cubic yards.
Tons: yd³ × 27 ft³/yd³ × density (lb/ft³) / 2000 lb/ton. Densities used: pea 96 lb/ft³, #57 clean 100, crusher run 115 loose, decorative river rock 95.
Practical order: exact × (1 + waste%/100), rounded UP to the next 0.25 yd³. Default 7% cushion absorbs transit settle, corner spillage, and supplier weight tolerance.
Compaction loss (compactable types only): 17.5% loose-to-compacted on crusher run / road base. Order loose depth = design depth × 1.20 to land at the design depth after compaction.

Frequently asked

How much gravel do I need for a driveway?

Plan for 8-12 inches of compacted depth, built in two or three layers depending on soil and traffic. For a 12 ft × 40 ft driveway on moderate soil — a 6 inch compacted base plus a 2 inch top dressing, 8 inches total at finish — the practical order is about 11.25 yards of crusher run (≈17.5 tons) plus 3.25 yards of #57 top stone. Layer specs: • Compacted crusher-run subbase — 4-6 inches. Order loose × 1.20 to land at finished depth. • Middle layer of #3 stone (heavy clay / higher-traffic spec) — bridges the subbase to the surface. • #57 stone top dressing — 2 inches, the finished crunchy surface. The math behind the example: 12 × 40 = 480 sq ft. Base at 7 inches loose crusher run → 10.37 yd³ exact (16.10 tons); with cushion, 11.25 yd³ or 17.47 tons. Top at 2 inches #57 → 2.96 yd³ exact; with cushion, 3.25 yd³. For any other driveway size: Use the calculator above. The engine swaps gravel type and depth by use case.

How many tons of gravel are in a cubic yard?

1.28 to 1.55 tons per cubic yard dry, depending on type. The calculator shows both yards and tons so you can confirm with whoever's dispatching. By type (dry loose density): • Decorative river rock — 1.28 tons/yd³. • Pea gravel — 1.30 tons/yd³. • #57 angular clean — 1.35 tons/yd³. • Crusher run loose — 1.55 tons/yd³. Denser still after compaction. Why industry ranges go higher: Some published ranges (e.g. 1.4-1.7 tons/yd³) sit above these midpoints because they include heavier dense-graded blends and wet loads. The calc uses dry loose density — the number that matches what an aggregate yard scoops onto your truck. Which unit your supplier uses: Aggregate suppliers bill by the ton. Landscape suppliers sometimes quote yards. The calc gives you both numbers to avoid confusion.

What size gravel is best for a driveway?

Crusher run for the subbase, #57 stone for the top dressing. Don't use rounded pea gravel as a driveway top. For the subbase — crusher run (also called road base or quarry process): The mix of fines and ¾-1 inch angular pieces packs and compacts into a stable load-bearing layer. For the top — #57 stone (¾ inch clean, no fines): Stays loose, drains, and gives the surface its finished crunch. What NOT to use as a top dressing — pea gravel: Rounded shape means vehicle tires shove it into ruts within a season. The calculator's presets: Driveway base defaults to 6 inches of crusher run. Driveway top defaults to 2 inches of #57.

How thick should a gravel driveway be?

8-12 inches of total compacted depth, built in three layers. Heavier soil = thicker subbase + non-negotiable geotextile underneath. On moderate clay or loam soil: 4-6 inch compacted crusher-run subbase at the upper end (6 inches), plus a geotextile separation fabric underneath. Total compacted thickness 10-12 inches. On heavy clay: Subbase has to be at least 8 inches. Geotextile is non-negotiable. What happens if you skip the geotextile: Fines from the soil migrate up into the gravel within a few rainy seasons. The driveway turns into a soft strip that won't drain.

Do I need a weed barrier or geotextile fabric under gravel?

For a driveway, yes — required on heavy clay, recommended everywhere else. For decorative beds, permeable landscape fabric helps but isn't the main weed-control move. For a driveway: Use a non-woven geotextile rated for driveway use (minimum 4 oz per square yard). Overlap joins by at least 12 inches. Pin the edges. For decorative beds: Permeable landscape fabric helps with weeds and lets water through. The bigger weed-control move is depth — 3 inches of mulch or stone over a clean prep does more than fabric over a half-prepped surface. What NOT to use: Plastic sheet under gravel. It traps water and the gravel migrates downhill on the slick layer.

How much does a yard of gravel cost?

Roughly $35-$65 per cubic yard delivered for the common types in the Chicago metro (2026 prices). Decorative river rock runs higher. Chicago-metro 2026 rule of thumb (delivery minimums vary by yard — often 3-5 yards or a ton equivalent; ask the dispatcher): • Crusher run — $35-$50 per yard. • #57 angular stone — $40-$55 per yard. • Pea gravel — $50-$65 per yard. • Decorative river rock — $80-$150 per yard, depending on size and color sort. Bagged from a big-box (0.5 cu ft per bag): Works out to 4-7× the per-yard price. Practical only for projects under one yard. What the calculator does and doesn't include: The output above gives yards and tons. Call your closest aggregate supplier for the day's price; confirm both yards and tons on the dispatch ticket.

What I'd do next

Topsoil for the lawn restore
After the gravel driveway and beds, the lawn restore is the closeout. The cushion math is similar; the depth presets are different.
Concrete yardage (slab, footing, post hole)
If the driveway is concrete instead of gravel — or if the gravel base is going under a slab — step over to the concrete calc.
Whole-project budget (rehab)
A driveway is one line on a bigger budget. The flagship surfaces every line for a residential gut rehab.

By James Wu. Volume math is site arithmetic, formulas above. Per-type loose bulk densities are midpoints from supplier spec sheets cross-checked against Omnicalculator (105 lb/ft³ default) and InchCalculator (1.4-1.7 tons/yd³ range). Driveway depth specs and geotextile guidance from USDA NRCS TN 210-AEN-04 — Earth and Aggregate Surfacing Design Guide (August 2017) and NRCS Construction Specification 495 — Geotextile. Earthfill + gravel-fill construction practices from NRCS Construction Specification 423 — Earthfill and Gravel Fill. Compaction loss range (15-20% loose-to-compacted on crusher run) cross-referenced against InchCalculator's “How to Account for Overage and Compaction” section. Engine logic in lib/sitework/gravel.ts. Not structural-engineering advice — for soil-bearing capacity, frost-line drainage, or any base prep under a structural slab, consult the local building inspector or a geotechnical engineer. Full methodology.

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Hi, I'm the SiteworkMath assistant. I answer questions about the calculators and guides on this site — concrete yardage, topsoil, mulch, tile, and decking material math. I'm not a structural engineer or a licensed contractor; I'm a calculator built around the math that James Wu — Chicago-area flipper — uses on his own jobs. For structural decisions (joist sizing, beam spans, footing depth in your soil + climate, anything that needs a permit) talk to a licensed structural engineer or your local building department.