How this gravel calculator works
Gravel is sold by weight (tons) or volume (cubic yards), and the difference between the two is density. The calculator computes the volume from your area and depth, applies the material's estimating density, then adds a compaction allowance:
tons = yd³ × density × (1 + compaction%) → rounded up to ¼ ton
Worked example: how much gravel for a 20 × 10 pad
20 × 10 ft at 3 in deep is 50 ft³ — 1.85 yd³. As crushed stone (1.4 t/yd³) with 10% compaction that's 2.85 tons, so you order 3 tons (about $135 at $45/ton) or 2.25 yd³ bulk. As bags it would take 110 half-cubic-foot bags — roughly $550.
How much does a ton of gravel cover?
Divide 19.3 ft³ (one ton of crushed stone) by your depth. The engine's coverage figures:
| Depth | Coverage |
|---|---|
| 2 in | ≈ 116 ft² |
| 3 in | ≈ 77 ft² |
| 4 in | ≈ 58 ft² |
| 6 in | ≈ 39 ft² |
How deep should gravel be?
- Paths & decorative beds: 2–3 in over landscape fabric keeps stone from disappearing into the soil.
- Patio & paver base: 4 in of compacted crushed base under the bedding sand — compacted in lifts, never dumped full-depth.
- Driveways: 4–6 in of base for cars; new construction over soft ground often runs 8 in+ in two layers (larger stone below, finer above).
- Drainage (French drains): the pipe wants 12 in of washed round stone, not crushed fines.
Gravel FAQ
How many tons of gravel are in a cubic yard?
About 1.4 tons for crushed stone and gravel, 1.3 for pea gravel, and 1.35 for river rock or sand — the standard estimating figures. Your quarry weighs the truck, so their ticket is the final word; these densities get the order right.
How much gravel do I need for a driveway?
A 50 × 10 ft driveway at 4 in deep needs 7 yd³, or about 9.75 tons of crushed stone with 10% compaction. New driveways want 4–6 in of base placed in compacted lifts — double the depth and the tonnage roughly doubles with it.
How much does a ton of gravel cover?
At 3 in deep, one ton of crushed stone covers about 77 ft²; at 2 in, about 116 ft²; at 4 in, 58 ft². The calculator shows the live coverage figure for whatever depth and material you set.
What is the difference between pea gravel and crushed stone?
Pea gravel is rounded, so it stays loose underfoot and rolls — good for paths and drainage, bad under anything structural. Crushed stone is angular and locks together when compacted, which is why driveway and paver bases specify it. It is also slightly denser: 1.4 vs 1.3 tons per yard.
Should I buy gravel in bags or bulk?
Bulk wins fast: the default 20 × 10 ft pad is 3 tons — about $135 delivered in bulk versus $550 as 110 half-cubic-foot bags. Bags only make sense for touch-ups and small paths under roughly half a yard.
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