How to calculate gravel
Suppliers sell gravel by volume (cubic yards) or by weight (tons), so you usually need both numbers. The calculator first finds the volume of the space you're filling, then converts it to weight using the typical density of the material you picked.
Cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27
Tons = cubic yards × weight per cubic yard (lb) ÷ 2,000
Example: a 40 × 10 ft driveway section filled 4 inches deep is 40 × 10 × 4 ÷ 12 = 133 cubic feet, or 4.9 cubic yards. At about 2,700 lb per yard, that's roughly 6.7 tons before any allowance for settling.
Typical weights of common materials
These are approximate dry weights. Wet material is heavier, and every quarry's product is a little different, so treat the ton figure as an estimate and confirm with your supplier.
| Material | Approx. lb per cu yd | Approx. tons per cu yd |
|---|---|---|
| Crushed stone / gravel | 2,700 | 1.35 |
| Pea gravel | 2,800 | 1.40 |
| River rock | 2,700 | 1.35 |
| Decomposed granite | 2,800 | 1.40 |
| Sand | 2,700 | 1.35 |
| Topsoil | 2,000 | 1.00 |
Recommended depths
| Use | Typical depth |
|---|---|
| Decorative top layer | 2–3 in |
| Garden path or patio | 3–4 in over a compacted base |
| Base under pavers or a shed | 4–6 in |
| New gravel driveway (all layers) | 8–12 in |
Ordering tips
- For an odd-shaped area, split it into rectangles and circles, run each one, and add the results together.
- Ask whether the price is per ton or per yard. Mixing these up is the most common ordering mistake.
- Delivery trucks have a maximum load. Large orders may need two trips, so check the delivery fee per load.
- Lay landscape fabric under decorative gravel to slow weeds and keep stone from sinking into the soil.
Frequently asked questions
How many tons of gravel are in a cubic yard?
Most gravel weighs about 1.3 to 1.5 tons per cubic yard (roughly 2,600 to 3,000 lb). The exact figure depends on the stone and how wet it is, so ask your supplier for the weight of the material they sell.
How deep should gravel be for a driveway?
Gravel driveways are commonly built in layers totaling 8 to 12 inches: a base of larger crushed stone, a middle layer, and a 2 to 4 inch top layer of smaller stone. Walkways and patios usually need 3 to 4 inches over a compacted base.
How much area does a ton of gravel cover?
At 2 inches deep, a ton of typical gravel covers roughly 100 square feet. At 4 inches it covers about half that. Enter your own depth above for an exact figure.
Is it cheaper to buy gravel by the ton or in bags?
For anything beyond a small bed or path, bulk gravel by the ton or yard is far cheaper than bags. Bags are convenient for small areas or when delivery isn't practical. Remember to ask about delivery fees when comparing.
Why add extra gravel?
Gravel settles and compacts after it's spread and driven on, and the ground underneath is rarely perfectly level. Adding 5 to 10 percent avoids a second delivery for a small top-up.