Stone and depth
Type feet and inches like 12'6" or just 12.5. Add a second area for an L-shaped drive, or tick Subtract for a patio inside it. Everything is saved on this device.
About the gravel calculator
This free gravel calculator tells you how much gravel you need for a driveway, a path, a patio base or a garden bed. Enter the size of the area and pick the project. You get the cubic yards (or m³), the tons to order and the number of bags.
Gravel is measured by volume but sold by weight. A cubic yard of crushed stone weighs about 1.4 tons, but lava rock weighs only half a ton. So choose your type of stone: the calculator uses its weight, and you can type your supplier's own figure. Add a price per ton to see the cost.
Features
- Cubic yards, tons, bags — and cubic feet and pounds, all at once
- 7 types of stone — crushed stone, pea gravel, crusher run, river rock, decomposed granite, sand and lava rock, each with its own weight
- Your own weight — type the tons per cubic yard from your supplier's sheet
- Project depths — driveway, new driveway, path, patio base, garden bed or French drain
- Any shape — rectangles, circles, triangles and trapezoids; add areas or subtract a patio
- Cost — by the ton (with delivery) or in bags
- Feet or metres — m³, tonnes and litre bags in metric
- Saved on this device — the list is still there at the supply yard
How deep should gravel be?
The right depth depends on what the gravel has to carry. These are the usual figures:
| Project | Depth | Good stone |
|---|---|---|
| Driveway — top layer on a firm base | 4 in (10 cm) | Crushed stone (#57) |
| New driveway — base and top | 6–8 in (15–20 cm), in layers | Crusher run, then crushed stone |
| Path or walkway | 2–3 in (5–7.5 cm) | Pea gravel or decomposed granite |
| Patio or paver base | 4–6 in (10–15 cm), packed down | Crusher run / paver base |
| Shed or hot tub base | 4–6 in (10–15 cm) | Crushed stone |
| Garden bed cover | 2 in (5 cm) | Pea gravel or river rock |
| French drain | the full trench, often 12 in (30 cm) or more | Washed crushed stone |
Put down gravel in layers of 3–4 inches and pack each layer with a plate compactor. Packed gravel takes up less room, so add 10–15% for compaction (under "Bags, delivery and compaction") when you build a base.
How much does gravel weigh?
| Stone | Tons per cubic yard | Pounds per cubic yard | Tonnes per m³ |
|---|---|---|---|
| Crushed stone (#57) | 1.4 | 2,800 | 1.66 |
| Pea gravel | 1.4 | 2,800 | 1.66 |
| Crusher run / road base | 1.5 | 3,000 | 1.78 |
| River rock | 1.35 | 2,700 | 1.60 |
| Decomposed granite | 1.4 | 2,800 | 1.66 |
| Sand | 1.35 | 2,700 | 1.60 |
| Lava rock | 0.5 | 1,000 | 0.59 |
These are averages for dry stone. Wet stone is heavier, and every quarry is a little different. If your supplier gives a figure, type it into the Weight box.
How far does a ton of gravel go?
One ton of crushed stone (1.4 tons per cubic yard) is about 19 cubic feet. Spread out, it covers:
| Depth | Area one ton covers |
|---|---|
| 2 in (5 cm) | about 115 sq ft (10.7 m²) |
| 3 in (7.5 cm) | about 77 sq ft (7.2 m²) |
| 4 in (10 cm) | about 58 sq ft (5.4 m²) |
| 6 in (15 cm) | about 39 sq ft (3.6 m²) |
Worked example and cost
The page opens on a 20 × 10 ft area, 4 inches deep — a parking pad or a short driveway:
- Area: 20 × 10 = 200 sq ft
- Volume: 200 × (4 ÷ 12) = 66.7 cubic feet = 66.7 ÷ 27 = 2.47 cubic yards
- Weight: 2.47 × 1.4 = 3.46 tons of crushed stone
- Bags: 66.7 ÷ 0.5 = 134 bags of 0.5 cu ft
Now the cost. Common crushed stone is often sold for roughly $30–$60 a ton at a landscape supply yard, and bags of 0.5 cu ft often cost $5–$8 each. Prices change a lot from place to place, so check yours:
| How you buy it | Cost for 3.46 tons |
|---|---|
| In bulk at $45 a ton | about $156, plus delivery |
| In 134 bags at $6 each | about $804 |
Cost tips:
- Above about one cubic yard, bulk is almost always cheaper than bags — even with a delivery fee.
- Ask what the delivery fee is and whether there is a minimum order (often 1–3 tons).
- Crusher run is cheaper than clean crushed stone and packs harder — use it for the base, and the nicer stone only on top.
- Decorative stone (river rock, colored gravel) costs more per ton, so keep it to the visible top layer.
- Put landscape fabric under paths and beds. It stops the gravel from sinking into the soil, so you buy less over the years.
How to use it
- Choose Feet & inches or Metres & cm
- Enter the length and width of the area, or choose another shape. Use Add another area for an L-shaped drive
- Pick the type of stone — or type your supplier's weight
- Pick the project to set the depth, or type your own depth
- Add a price per ton to see the cost (bags, delivery and compaction are in the fold-out)
- Read the cubic yards, tons and bags — and press Copy the list
Frequently asked questions
How much gravel do I need?
Multiply the length × width × depth to get the volume, then multiply by the weight of the stone. A 20 × 10 ft driveway 4 inches deep needs 2.47 cubic yards — about 3.5 tons of crushed stone.
How many tons of gravel are in a cubic yard?
About 1.4 tons (2,800 lb) for crushed stone and pea gravel, 1.5 tons for crusher run and 1.35 tons for river rock and sand. Lava rock is much lighter: about half a ton.
How many bags of gravel make a cubic yard?
54 bags of 0.5 cubic feet make one cubic yard (27 cubic feet). One ton of crushed stone is about 39 bags of 0.5 cu ft.
How much gravel do I need for a driveway?
Use 4 inches of crushed stone on a firm base. A driveway 50 ft long and 10 ft wide needs 6.2 cubic yards — about 8.6 tons. A new driveway on soft ground needs a base too: 6–8 inches in total.
How deep should gravel be for a patio base?
Use 4–6 inches of crusher run or paver base, packed down in layers, with about an inch of sand on top for pavers.
Is pea gravel good for a driveway?
Not on its own. Pea gravel is round, so it rolls and moves under car tires. Angular crushed stone locks together and stays put. Pea gravel is better for paths, beds and play areas.
Can I use metres and tonnes?
Yes. Switch to Metres & cm to get m³, tonnes and litre bags. One m³ of crushed stone weighs about 1.66 tonnes.
Related tools
- Mulch, Soil & Gravel Calculator — mulch, topsoil and compost for garden beds
- Concrete Calculator — bags or yards of concrete for a slab
- Square Footage Calculator — the area of a yard or a lawn
- Tile & Flooring Calculator — pavers and tiles for a patio
- Unit Converter — tons, cubic yards and cubic metres
