Gravel Calculator
Cubic yards, tons and bags — with the compaction allowance base material actually needs.
Gravel to order
7.41 yd³
- Area
- 480 sq ft
- Finished volume
- 5.93 yd³
- Compaction allowance (20%)
- +1.48 yd³
- Order by weight
- 11.11 tons
- Loose volume
- 200 ft³
- Bagged equivalent
- 400 bags (0.5 ft³)
- Coverage at 4.0 in
- 81 sq ft per yd³ · 54 sq ft per ton
Bulk yards round to the half or full yard, and trucks have minimum loads — confirm both before ordering.
Need soil rather than stone? Use the topsoil calculator →
How this is calculated
area = L × W (or entered directly) finished = area × depth(in)/12 / 27 order = finished / (1 − compaction%) tons = order × density / 2,000 coverage = 27 / (depth(in)/12) sq ft per yd³
Depth is the finished, compacted depth, so the order is divided by the compaction factor rather than multiplied by it — a 20% loss means ordering 25% more, not 20% more, and that difference is a real quarter-yard on a small job. Metric input converts at 1 m = 3.28084 ft, 1 m² = 10.7639 sq ft and 1 cm = 0.393701 in.
Gravel weight and compaction by material
| Material | Density | Tons per yd³ | Compaction |
|---|---|---|---|
| Pea gravel | 2,800 lb/yd³ | 1.40 | 5% |
| Crushed stone #57 (3/4") | 2,700 lb/yd³ | 1.35 | 8% |
| Crusher run / road base | 3,000 lb/yd³ | 1.50 | 20% |
| River rock | 2,650 lb/yd³ | 1.33 | None |
| Decomposed granite | 2,900 lb/yd³ | 1.45 | 15% |
| Limestone screenings | 2,800 lb/yd³ | 1.40 | 15% |
| Lava rock | 1,300 lb/yd³ | 0.65 | None |
Coverage per cubic yard
| Depth | Coverage per yd³ | Yd³ per 100 sq ft |
|---|---|---|
| 1 in | 324 sq ft | 0.31 |
| 2 in | 162 sq ft | 0.62 |
| 3 in | 108 sq ft | 0.93 |
| 4 in | 81 sq ft | 1.23 |
| 6 in | 54 sq ft | 1.85 |
| 8 in | 41 sq ft | 2.47 |
These are finished depths before any compaction allowance. A driveway built as a 6 inch base plus a 3 inch surface layer is two separate calculations, not one at 9 inches, because the two layers usually use different stone at different densities.
Frequently asked questions
How much gravel do I need?
Multiply the area in square feet by the depth in feet to get cubic feet, then divide by 27 for cubic yards. One cubic yard covers about 108 square feet at 3 inches deep, or 81 square feet at 4 inches. Order by the ton if your supplier prices that way, since most bulk yards sell stone by weight rather than volume.
How much does a yard of gravel weigh?
Most gravel runs 2,600 to 3,000 lb per cubic yard, so roughly 1.3 to 1.5 tons. Crusher run sits at the top of that range because the fines fill the voids between stones, and lightweight decorative material like lava rock is far below it at around 1,300 lb. The density field is editable because this number decides both your delivery cost and whether a load is legal on your truck.
How deep should a gravel driveway be?
A residential driveway wants 8 to 12 inches of total stone, normally built in layers: a coarse base of 4 to 6 inches, a middle layer, then 2 to 3 inches of surface stone. A single thin layer over soft ground will rut within a season no matter how good the stone is, because the failure is in the subgrade rather than the surface.
Do I need to order extra for compaction?
For base material, yes. Crusher run and road base lose roughly 20% of their loose volume once rolled, so a compacted four inch layer needs about five inches of loose stone delivered. Rounded decorative stone such as river rock barely compacts at all, and ordering extra for it just leaves you with a leftover pile.
Is gravel cheaper by the ton or by the yard?
It is the same stone, only measured differently, so compare on delivered cost per cubic yard after converting. Yards that quote by the ton often look cheaper until the density is applied — at 1.4 tons per yard, $40 a ton is $56 a yard. Delivery is usually a flat haul fee per truck, so part loads carry the same trip cost as full ones.
Should I put fabric under gravel?
Under a driveway or path over soft ground, yes. Geotextile separates the stone from the soil so the base does not sink into it and the subgrade does not pump up through the stone. It is one of the cheapest items in the job and the most common one skipped, and its absence is why so many gravel drives need topping up every year.
Results are planning estimates. Densities vary by quarry, stone size and moisture, and wet material weighs materially more than the same load dry. Confirm the density and the minimum load with your supplier, and check axle limits before hauling stone yourself.