Gravel Calculator
Calculate the tons of gravel needed for a driveway, path or bed.
What you'll need to order
- gravel
- geotextile fabric
- edging
Prices vary by region and haul distance. Get quotes from at least two local suppliers.
How this calculator works
tons = length × width × (depth ÷ 12) × 105 ÷ 2000
Gravel weighs about 105 lb per cubic foot, roughly 1.4 tons per cubic yard. Suppliers sell by the ton or the yard depending on region, so it pays to know both figures before you call.
Worked example
With length 10 ft, width 10 ft, depth 3 in, this calculator returns 1.31 tons.
Gravel coverage by depth
Figures below assume length 10 ft × width 10 ft. Change any measurement in the calculator to get your own numbers.
| Depth | Gravel needed (tons) | Volume (cu yd) |
|---|---|---|
| 1 in | 0.44 | 0.31 |
| 2 in | 0.87 | 0.62 |
| 3 in | 1.31 | 0.93 |
| 4 in | 1.75 | 1.23 |
| 6 in | 2.63 | 1.85 |
| 8 in | 3.50 | 2.47 |
| 12 in | 5.25 | 3.70 |
Per 100 square feet. Multiply by your own area in hundreds of square feet — a 600 sq ft area at 4 inches needs six times the 4-inch row.
How much gravel for a driveway, path or slab base?
| Job | Size | Gravel needed | Material cost |
|---|---|---|---|
| Garden path 3 ft wide, 3 in deep |
40 ft × 3 ft × 3 in | 1.57 tons | $32 – $95 |
| Shed or hot tub base | 12 ft × 10 ft × 4 in | 2.10 tons | $42 – $126 |
| Base under a concrete slab compacted sub-base |
20 ft × 20 ft × 4 in | 7.00 tons | $140 – $420 |
| French drain trench | 50 ft × 1.5 ft × 12 in | 3.94 tons | $79 – $236 |
| Single-car driveway two 4 in layers |
50 ft × 10 ft × 8 in | 17.50 tons | $350 – $1,050 |
| Two-car driveway two 4 in layers |
24 ft × 20 ft × 8 in | 16.80 tons | $336 – $1,008 |
Driveway figures assume the full build-up. If you are topping up an existing drive, use the depth you are adding, not the total.
Cost range uses $20–$60 per ton for material only.
What does gravel cost?
Material typically runs $20 to $60 per ton. Delivered but not spread. Spreading and compaction by a contractor typically adds $25 to $50 per ton.
What moves the price:
- Stone type — crusher run is cheapest, decorative river rock and lava rock cost several times more
- Haul distance from the quarry, which often matters more than the stone itself
- Load size — a full tandem load is far cheaper per ton than a part load
- Washed versus unwashed material
Prices are US averages and move with fuel, season and haul distance. Always get two local quotes before budgeting.
Gravel types and how much they weigh
| Type | Weight (lb per cu ft) | Notes |
|---|---|---|
| Crusher run / road base | 125.0 | Compacts hard, best for driveway sub-base |
| Crushed stone #57 | 100.0 | Drains freely, standard under slabs |
| Decomposed granite | 108.0 | Path surfacing, compacts to a firm finish |
| River rock | 98.00 | Decorative, does not compact |
| Pea gravel | 96.00 | Rounded, migrates underfoot without edging |
| Lava rock | 50.00 | Very light — halves the tonnage for the same volume |
This calculator uses 105 lb per cubic foot, a mid-range figure for common gravel. If you know your product, scale the result: lava rock at 50 lb needs less than half the tonnage.
Gravel calculation questions
How much gravel do I need?
Multiply area in square feet by depth in feet, then by 105, then divide by 2,000. A 40 by 12 ft driveway at 4 inches deep needs about 8.4 tons.
How do I calculate cubic yards of gravel?
Multiply length by width by depth in feet to get cubic feet, then divide by 27. A 40 by 12 ft area at 4 inches deep is 160 cubic feet, or 5.93 cubic yards.
How many tons in a yard of gravel?
About 1.4 tons, since a cubic yard weighs roughly 2,835 lb. Wet gravel runs heavier, and suppliers quote by dry weight.
How much gravel do I need under a concrete slab?
Four inches of compacted crushed stone is standard under a residential slab, six inches on poor or clay soil. A 20 by 20 ft slab needs about 7 tons at 4 inches.
How much gravel does a dump truck hold?
A tandem axle truck carries 10 to 14 cubic yards by volume, but weight usually limits the load first — around 14 tons. Most yards charge per load, so a full load is cheaper per ton.
What depth of gravel for a driveway?
Eight to 12 inches total, built in 4 inch layers and compacted separately. A single deep layer never compacts through, which is the most common reason gravel driveways rut.
How much does a yard of gravel cover?
One cubic yard covers 162 square feet at 2 inches deep, 108 sq ft at 3 inches, and 81 sq ft at 4 inches. Divide 324 by your depth in inches to get the coverage in square feet.
Should I order by the ton or by the yard?
Order the way your supplier sells. Weight is the more reliable measure because loose volume changes with moisture and how the load settles — but always confirm which one the quoted price refers to.
How much extra gravel should I order?
Add 5 to 10 percent. Material is lost to uneven subgrade, spillage at the edges and settling into soft ground. Running short means paying a second delivery charge for a fraction of a load.
Do I need landscape fabric under gravel?
Yes, on anything that will bear weight. Geotextile fabric stops the stone from working down into the soil, which is what turns a 4 inch layer into a 2 inch layer after two winters.