Gravel Calculator
Work out how many tons and cubic yards of gravel to order for a driveway, path or bed from its length, width and depth, with the packing allowance built in.
Gravel is sold by the ton or the cubic yard, and a base of crushed stone packs down after it's spread, so the amount you order isn't the amount that ends up on the ground. This turns your measurements into tons and yards to order, with the packing allowance built in for the materials that need it.
The area
Measure the area you're covering. A two-car driveway is about 20 × 40; a single lane to the road might be 12 × 50. For a circle or an odd shape, use the rectangle that just contains it.
Length
Width
How deep
A driveway base is 4 inches of crushed stone, packed down, with 2 to 4 inches of top gravel over it. A path or a bed of decorative gravel is 2 to 3 inches. A shed pad is 4 to 6.
What kind of gravel
Crushed stone has sharp edges and fines that lock together when packed, which is why it's the base under everything. The rounded kinds stay loose and are for the top or for looks.
Order about
15.8 tons
9.9 cubic yards loose (7.4 packed down) of crushed stone for 600 sq ft at 4 in
A driveway is two layers, and this is one of them
This order is the base: crushed stone with its fines, spread loose, then packed with a plate compactor or a roller until it's a third thinner and hard underfoot. The road guides place it 6 to 8 inches loose to get 4 to 6 packed, in one lift, at the damp-but-not-wet moisture where it locks. On top goes 2 to 4 inches of the gravel you actually see: clean stone or pea gravel, run through this calculator again as a second order. Ask the quarry for "crusher run," "dense-graded" or "3/4 minus"; a truck delivers by the ton, and the scale ticket, not the estimate, is what you pay for.
Yards are length × width × depth ÷ 27. Crushed stone for a base is ordered a third over the finished depth, because an 8-inch loose lift packs to 6; rounded gravels get no allowance. Tons per loose yard: crushed stone 1.6, clean stone 1.35, pea gravel 1.3, river rock 1.4; wet stone weighs more, so treat tons as within 15 percent. 2026 figures.
💡About this calculator▼
Gravel is sold by the ton or the cubic yard, and the order is never quite the number you get from length times width times depth. Crushed stone for a driveway base packs down by about a third once it's spread and compacted, so you buy more than ends up on the ground; decorative gravel doesn't pack at all. And a yard of crushed stone weighs more than a yard of pea gravel.
This gives you the order. Enter the length and width of the area, how deep you want it, and the kind of gravel. You get the tons to order, the cubic yards, the bag count if you're buying small, and a check that the depth makes sense for what you're building.
The two-layer driveway is where people go wrong. A gravel driveway is 4 inches of packed crushed stone with 2 to 4 inches of the gravel you see on top. Order the base with the packing allowance, then run the top layer as a second order without it, and you'll have a driveway that stays put instead of one that sinks into the mud by spring.
Start with the volume. Length times width times depth in inches, divided by 12 to get feet and by 27 to get cubic yards, is the volume in place. A 50 by 12 foot lane at 4 inches is 7.4 cubic yards.
Add the packing allowance for crushed stone. Crushed stone has sharp edges and fine particles that lock together under a plate compactor, and the road-building guides place it 8 inches loose to get 6 inches packed. So for a base you order the in-place volume times eight-sixths, a third more: 9.9 loose yards for that lane. Clean stone, pea gravel and river rock are rounded and stay loose, so their order is the in-place volume.
Convert to tons. Suppliers sell by weight, and a loose cubic yard weighs about 1.6 tons for crushed stone (the road guide's ordering rule works out to that figure), 1.35 for clean stone, 1.3 for pea gravel and 1.4 for river rock. Wet material weighs more, so the truck's scale ticket is the real number and the estimate is within about 15 percent.
Check the depth. A crushed-stone base needs 4 inches packed, and decorative gravel needs about 2 inches to cover, so the calculator flags orders thinner than that.
Worked example. The default 50 by 12 foot driveway lane at 4 inches of crushed stone: 600 square feet × 4 ÷ 12 ÷ 27 = 7.4 cubic yards in place; × 8/6 = 9.9 loose yards to order; × 1.6 = 15.8 tons, or about 534 half-cubic-foot bags. At 6 inches packed the same lane is 23.7 tons, which matches the road guide's rule of width × length × 0.04.
📐How it's calculated▼
Cubic yards in place = length × width × depth ÷ 12 ÷ 27.
Cubic yards to order = in place × 8/6 for crushed stone (a 33 percent packing allowance); × 1 for clean stone, pea gravel and river rock.
Tons = loose cubic yards × density: crushed stone 1.6, clean (#57) stone 1.35, pea gravel 1.3, river rock 1.4 tons per loose yard.
Bags = loose cubic feet ÷ 0.5.
Depth check: crushed stone under 4 inches or decorative gravel under 2 inches is flagged.
Default (50 × 12 ft, 4 in, crushed): 7.4 yd in place → 9.9 yd loose → 15.8 tons, 534 bags.
Same lane at 6 in: 11.1 yd → 14.8 loose → 23.7 tons (the road guide's rule gives 24).
Pea gravel path, 30 × 3 ft at 2 in: 0.6 yd → 0.7 tons, 30 bags.
River rock bed, 20 × 10 ft at 3 in: 1.9 yd → 2.6 tons.
📎Sources:Penn State Center for Dirt and Gravel Road Studies — Driving Surface Aggregate Handbook (placement depth, compaction, tons to order),PennDOT LTAP — Tech Sheet 186, Maintenance of Gravel Roads (loose lift depth),Hello Gravel — How Deep Should Driveway Gravel Be? (base and surface layer depths)
🔍Finding your inputs▼
Length and width: Measure the area you're covering in feet. A single lane to the road is about 12 wide; a two-car parking area 20 by 40. For a circle or an odd shape, use the rectangle that just contains it; it over-orders a little, which is the right direction.
How deep: For a driveway base, 4 inches of crushed stone, packed. For the top layer of a driveway, 2 to 4 inches of the gravel you see. For a path or a decorative bed, 2 to 3 inches over landscape fabric. For a shed pad, 4 to 6 inches. The calculator flags a base under 4 inches and a decorative layer under 2.
What kind of gravel: Crushed stone (sold as crusher run, dense-graded, road base or 3/4-inch minus) has sharp edges and fines that pack into a slab; it's the base under a driveway, and the only kind that gets the packing allowance. Clean stone (#57) is crushed but washed of fines, so it drains and doesn't pack: shed pads, French drains, the top of a driveway. Pea gravel and river rock are rounded and decorative: paths, beds, borders.
⚠️Special situations▼
I only need a small amount. Bags or a delivery?
Up to about a cubic yard, bags: a 30-foot path at 2 inches is 30 half-cubic-foot bags, an afternoon's carrying. Past two yards, get it delivered; a ton of gravel bagged costs several times what a ton dumped in the driveway does, and most yards have a one-ton minimum that a small bed still fits inside. In between, a pickup load from the yard, about a yard at a time if the truck is rated for it, splits the difference.
The quarry quoted me a different tonnage for the same yards.
Their density is different, and theirs is the one you'll pay. Crushed stone runs anywhere from 1.4 to 1.7 tons a loose yard depending on the rock and how wet it is, and a supplier's online calculator may use a dry figure near 1.2 for everything. This calculator uses 1.6 for crushed stone, the figure the road-building guide's ordering rule works out to, so a quote within 15 percent either way is the same order. Order by the yard if you want the volume fixed; the tons will follow the scale.
Do I really need to order a third more for a driveway base?
Yes, if you want the depth you planned. The road guides place crushed stone 8 inches loose to get 6 inches packed, and 6 loose to get 4½, because the fines settle into the gaps under the compactor. Skip the allowance and your 4-inch base is a 3-inch base once it's rolled, which is under the minimum. Decorative gravel doesn't do this: rounded stone has no fines and stays the depth you spread it, which is why the calculator only adds the allowance to crushed stone.
I'm topping up an existing driveway, not building one.
Then you're ordering the top layer only: pick clean stone or pea gravel, 2 to 3 inches, and skip the base allowance. Most driveways need a top-up every three to five years as gravel migrates to the edges. If the existing surface has ruts or soft spots, that's the base failing underneath, and a top-up will sink into it; scrape the ruts, add crushed stone to the low spots and compact before the new top goes on.
❓Common questions▼
How much gravel do I need for a driveway?
Length times width times depth ÷ 12 ÷ 27 gives cubic yards in place, plus a third more for a crushed-stone base because it packs down, then times 1.6 tons per loose yard. A 50 by 12 foot lane needs about 16 tons of crushed stone for a 4-inch packed base, and about 7.5 tons of clean stone for a 3-inch top layer; a 40 by 20 two-car area needs about 21 tons of base. The road guides put a finished driveway at 6 to 8 inches total: 4 of base, 2 to 4 on top.
How many tons is a cubic yard of gravel?
About 1.6 tons for crushed stone and crusher run, 1.35 for clean #57 stone, 1.3 for pea gravel and 1.4 for river rock, per loose cubic yard as delivered. The spread between suppliers comes from moisture and the rock itself: a dry, loose figure runs about 1.2, wet crushed granite can pass 1.7. The quarry's scale ticket is what you pay for, so treat any estimate as within 15 percent.
How deep should gravel be?
A driveway is two layers: 4 inches of packed crushed stone as the base, then 2 to 4 inches of the gravel you see on top, 6 to 8 inches in all. A path or a decorative bed over landscape fabric is 2 to 3 inches. A shed pad of clean stone is 4 to 6. The road-building guides place base stone 8 inches loose to get 6 packed, or 6 loose to get 4½, always in one lift; thinner lifts don't lock together.
What is the difference between crushed stone, clean stone and pea gravel?
Crushed stone, sold as crusher run, dense-graded or 3/4 minus, is angular rock with the fines left in, so it packs into a hard slab; it's the base under a driveway. Clean stone, #57 being the common size, is the same crushed rock washed of fines, so water runs through it and it never packs: French drains, pads, driveway tops. Pea gravel and river rock are rounded stones from riverbeds, decorative, and they roll rather than lock, so they belong on paths and beds, not under a car.
Is it cheaper to buy gravel by the bag or by the ton?
By the ton, by a wide margin, once you're past a couple of cubic yards. A half-cubic-foot bag holds about 40 pounds, so a ton is roughly 50 bags, and bagged gravel typically costs several times the delivered price per ton. Bags win only for a small bed, a repair or a spot a truck can't reach; most yards will deliver a single ton, and a pickup rated for it can carry about a yard from the yard.
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