Gravel Calculator
Working out a gravel order means two separate jobs: figuring out the volume your project needs, then converting that volume into the weight your supplier actually sells by. This calculator does both. Pick your gravel type for a realistic density (or type in your supplier's own figure), enter your area and depth in any unit, add a compaction buffer so you don't come up short, and get your total in cubic yards, tons, and cost.
There's no universal tons-per-yard figure — density depends on the material and your supplier.
Default for Crushed stone #57: 2,431 lb/yd³ (≈ 1,442 kg/m³). Leave blank to use it, or enter your supplier's figure.
Loose gravel shrinks when tamped. Add ~8–10% for open-graded stone, ~15–20% for dense-graded base like DGA.
Your gravel volume and tonnage will appear here
Pick a gravel type, enter your area dimensions and depth, then click calculate.
Quick Answer
Volume = area × depth. Convert that to cubic yards (÷ 27), then multiply by the material's density to get weight, and divide by 2,000 for US tons. There is no single tons-per-yard value — density changes with the stone type, its size, and moisture — so this calculator lets you pick a material or enter your own density.
How It Works: Formula & Variables
Weight (tons) = (Area × Depth ÷ 27) × Density ÷ 2,000
- Area (rectangle)
- length (ft) × width (ft)
- Area (circle)
- π × (diameter ÷ 2)²
- Area (ring / annulus)
- π × (R_outer² − R_inner²)
- Depth in feet
- depth in inches ÷ 12
- Volume
- ft³ = area × depth; yd³ = ft³ ÷ 27
- Weight
- lb = yd³ × density (lb/yd³); tons = lb ÷ 2,000
Typical densities (default values, override for your supplier)
There is no universal tons-per-yard value — density is material- and supplier-dependent, varying with stone size and moisture.
| Gravel type | lb/yd³ | kg/m³ |
|---|---|---|
| Pea gravel | 2,565 | 1,522 |
| River rock | 2,835 | 1,682 |
| Crushed stone #57 | 2,431 | 1,442 |
| Crushed stone #411 | 2,835 | 1,682 |
| Decomposed granite | 2,781 | 1,650 |
| Dense graded (DGA/QP) | 3,374 | 2,002 |
| Bank run gravel | 3,240 | 1,922 |
| Lava rock | 1,391 | 825 |
| Marble chips | 2,565 | 1,522 |
| Riprap | 2,700 | 1,602 |
Worked Examples
Example: gravel driveway
A driveway 20 ft × 10 ft, 3 inches deep, using crushed stone #57:
- Area: 20 × 10 = 200 ft²
- Depth in feet: 3 ÷ 12 = 0.25 ft
- Volume: 200 × 0.25 = 50 ft³
- Volume in yd³: 50 ÷ 27 = 1.85 yd³
- Weight at 2,431 lb/yd³: 1.85 × 2,431 = 4,502 lb ≈ 2.25 US tons
Always add a settling/compaction buffer on top: open-graded stone about 8–10% (× 1.10), dense-graded base material about 15–20% (× 1.20). For this driveway, that means ordering a realistic 2.0–2.2 yd³ rather than the bare geometric 1.85 yd³.
Key Concepts
Density isn't one number: A cubic yard of lava rock weighs less than half what dense-graded base does. Density shifts with the stone type, its size, and how wet it is, so pick your material or enter the figure your supplier gives you.
Volume in, weight out: Your project is a volume you fill, but gravel is sold by weight. Every order comes down to converting cubic yards into tons through the material's density.
Order loose, deliver compacted: Base gravel is meant to be tamped down hard, which is why dense-graded material needs a bigger buffer than decorative stone you just rake into place.
Common Mistakes
Leaving depth in the wrong unit: Entering depth in inches while your area is in feet throws the whole result off. Depth always has to be divided by 12 to bring it into feet first — this calculator handles that for you as long as you pick the right unit.
Ignoring compaction: Skipping the settling buffer is the fastest way to come up short, especially on a base course that gets heavily tamped.
Assuming one tons-per-yard figure: Reusing a single density for every material leads to badly wrong orders, since it swings a lot with the stone and its moisture.
Ordering by weight before converting: Trying to buy by the ton without first turning your volume into weight skips the one step that ties your project size to what the supplier loads.
Frequently Asked Questions
That depends entirely on how deep you're going. Multiply your area by your depth (in the same unit) to get volume, then multiply that volume by the material's density to get weight. A square foot at 2 inches deep needs far less than the same square foot at 6 inches, so depth is what really drives the number.
Usually around 1.4 to 1.5 tons (roughly 2,800 to 3,000 lb) for crushed gravel. Pea gravel runs lighter at about 1.2 to 1.4 tons, and lava rock is much lighter still at around 0.65 to 0.9 tons per yard. Because the range is so wide, it's always worth confirming the exact figure with your supplier.
Yes. Gravel is delivered loose and shrinks once it's tamped down, so order a little extra. Around 10% more works for open-graded decorative stone, and 15 to 20% more is safer for dense-graded base material that gets heavily compacted.
Tons equals cubic yards multiplied by the density in tons per yard. For example, 10 cubic yards of gravel at 2,800 lb per yard is 28,000 lb, which comes to 14 tons. The calculator does this for you once you pick a material or enter your own density.
Your project is a volume — length times width times depth — but suppliers price and load material by weight. That's why you always have to convert volume into weight using the density of the specific stone you're buying, rather than assuming one figure fits everything.
A surface layer is typically 2 to 4 inches (about 5 to 10 cm). A compacted base layer runs deeper, around 4 to 8 inches (10 to 20 cm). A common driveway depth is 3 inches for the top course over a prepared base.
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