Gravel Calculator
A {length}×{width} ft area covered {depth} in deep in {material} needs about {cubicYards} cubic yards, or {tons} tons.
Gravel needed for common project sizes
| Area | Depth | Material | Cubic yards | Tons |
|---|---|---|---|---|
| 10×10 ft | 2 in | Gravel | 0.68 | 0.95 |
| 20×3 ft (path) | 3 in | Gravel | 0.61 | 0.86 |
| 50×10 ft (driveway) | 4 in | Gravel | 6.79 | 9.51 |
| 100×10 ft (driveway) | 4 in | Gravel | 13.58 | 19.01 |
| 20×20 ft (parking pad) | 4 in | Gravel | 5.43 | 7.60 |
| 30×12 ft | 4 in | Gravel | 4.89 | 6.84 |
| 12×24 ft (RV pad) | 6 in | Gravel | 5.87 | 8.21 |
| 50×10 ft (driveway) | 4 in | Crusher run | 6.79 | 10.19 |
| 50×10 ft (driveway) | 4 in | #57 stone | 6.79 | 9.85 |
Includes 10% extra for settling and an uneven subgrade. Tons vary by material density; see the table below.
How the math works
Gravel coverage is the same volume math as a slab — area times depth — then converted to tons using the material's bulk density, since gravel and stone are almost always sold by weight or by the cubic yard rather than by bag.
cubic yards = cubic feet ÷ 27
tons = cubic yards × density (tons per cubic yard)
Density varies by material: about 1.40 tons per cubic yard for gravel and pea gravel, 1.50 for crushed stone, crusher run and limestone, 1.35 for sand and river rock, and 1.10 for topsoil, which is lighter and looser. See our tons-to-yards converter for the full density table.
This calculator multiplies volume by a density figure to give you tons — and that density is a typical value, not a measurement of the specific material you're about to buy. Three things routinely move it: which quarry the material came from, how it's graded (a well-graded mix with fines packs denser than a uniform open-graded stone of the same rock), and moisture. Moisture is the biggest everyday factor — density is quoted per volume, and water adds mass without adding volume, so wet material means less actual stone per ton than the dry figure implies. A supplier quoting a dry density and delivering wet material isn't being dishonest; the number was just measured under different conditions. Ask your supplier whether their quoted density is dry or as-shipped, and treat the figures here as a planning range rather than an exact conversion.
Angular vs. rounded — not interchangeable under a slab
| Angular (crushed) | Rounded (river/pea gravel) | |
|---|---|---|
| Particle shape | Fractured faces, sharp edges | Smooth, water-worn |
| Compaction | Compacts into a stable, load-bearing mass | Doesn't meaningfully compact — it just rearranges |
| Load bearing | Suitable as a structural base | Not suitable as a structural base |
| Best for | Base course, driveways, under slabs | Drainage, decorative, pipe bedding |
Pea gravel under a slab or driveway is one of the more common costly mistakes in residential work. It looks like gravel and is sold as gravel, but because it's rounded, it can't be compacted into a structural base — it just keeps rearranging under load. Whatever sits on top of it then settles unevenly over time, and the failure usually gets blamed on the concrete rather than the base underneath it. If you're picking a base material, choose an angular product — crusher run, #57 stone, or crushed stone — not pea gravel or river rock.
Order for loose volume, not the finished compacted depth
A compactor only densifies material to a limited depth, so a thick layer placed in one pass tends to leave the bottom uncompacted — exactly where the load ends up. The standard approach is to place material in two or more lifts, compacting each one before adding the next. But there's a volume consequence to this that catches people off guard: compacted material occupies noticeably less volume than the same material placed loose. If you enter "4 inches" here meaning the finished, compacted depth you want, you need to order for a somewhat greater loose depth to actually achieve it once compacted — this calculator computes loose volume from the depth you enter, so build in extra when your goal is a specific finished, compacted thickness.
Before you buy
- Order 5 to 10% extra to cover an uneven subgrade and material lost to compaction settling.
- For a driveway base, use an angular material like crusher run or #57 stone rather than smooth pea gravel — angular pieces interlock and stay put under vehicle weight.
- Compact in lifts of 2 to 4 inches rather than dumping the full depth at once, especially over soft or wet soil.
- Ask your supplier whether their price is per ton or per cubic yard, and use the matching output above — they're not interchangeable across materials.
- Bulk delivery minimums are often 5 to 10 tons; for smaller amounts, bagged gravel from a hardware store may work out cheaper despite the higher per-pound price.
Common questions
How much gravel do I need for a driveway?
Multiply length by width by depth (in feet), then convert to cubic yards or tons. A 50×10 ft driveway covered 4 inches deep needs about 6.8 cubic yards, or roughly 9.5 tons of gravel.
How deep should a gravel driveway be?
4 inches is typical for a single compacted layer on an established base. A new driveway over soft soil often uses two layers, a coarser 4-inch base plus a 2-inch topping, for 6 inches total.
How much does gravel weigh per cubic yard?
Around 2,800 lb, or 1.4 tons, for typical bank-run or crushed gravel. Denser materials like crusher run or limestone weigh closer to 1.5 tons per yard, and looser material like topsoil weighs less.
Should gravel be measured in tons or cubic yards?
Landscaping suppliers usually sell gravel by the cubic yard, while quarries and larger deliveries price it by the ton. This calculator gives both so you can order from either type of supplier.
Do I need to compact gravel after spreading it?
Yes, for any driveway, patio base, or walkway. Compacting removes air gaps so the layer doesn't settle unevenly under weight later. Loose material can settle 10 to 20% after compaction, so order a little extra if you're not compacting in lifts.