How the calculation works
Gravel is sold by volume (cubic yards or cubic metres) or by weight (tons or tonnes). The calculator finds the volume of your area, adds compaction for stone that packs down, adds overage, and converts to weight using the density of the stone you picked.
Worked example
A 20 × 10 ft path at 4 inches deep is 200 ft² × 0.333 ft = 66.7 ft³. Divide by 27 and you get 2.47 cubic yards. In 3/4" clear crushed stone at 1.35 tons per yard, that is 3.33 tons. Add 10% overage and you should order about 3.7 tons, or 2.7 yards.
How to measure
Measure depth as the finished thickness of gravel, not the depth of the hole. If you're laying a base and a top layer, run the calculator once for each. For an odd-shaped area, split it into rectangles and circles, add up the square footage, and use "I know the area".
How deep should gravel be?
| Project | Depth | Usual material |
|---|---|---|
| Garden path | 2–3 in · 5–7.5 cm | Pea gravel |
| Walkway | 3–4 in · 7.5–10 cm | Decomposed granite |
| Patio or paver base | 4–6 in · 10–15 cm | Packing base (road base, 3/4" minus) |
| Driveway top layer | 2–4 in · 5–10 cm | Crushed stone (3/4" clear) |
| Driveway base | 4–8 in · 10–20 cm | Packing base (road base, 3/4" minus) |
| French drain | 12 in+ · 30 cm+ | Drain rock (1.5" clear) |
| Decorative bed | 2–3 in · 5–7.5 cm | River rock |
Soft clay or heavy trucks call for a deeper base. Ask your supplier what works locally.
Gravel weight by type
These are typical loose weights. Every quarry's stone is a little different, so check your supplier's figure if you're ordering by the ton.
| Material | Tons / yd³ | Tonnes / m³ | Compaction added | Bag size |
|---|---|---|---|---|
| Crushed stone (3/4" clear) | 1.35 | 1.60 | None | 0.5 cu ft |
| Packing base (road base, 3/4" minus) | 1.40 | 1.66 | +15% | 0.5 cu ft |
| Pea gravel | 1.40 | 1.66 | None | 0.5 cu ft |
| Drain rock (1.5" clear) | 1.30 | 1.54 | None | 0.5 cu ft |
| River rock | 1.30 | 1.54 | None | 0.5 cu ft |
| Decomposed granite | 1.30 | 1.54 | +10% | 0.5 cu ft |
Bags or bulk delivery?
Bagged gravel usually comes in 0.5 ft³ bags weighing about 50 lb. Fifty-four of those make one cubic yard. Bags make sense for a planter or a small patch. Past roughly half a yard, bulk delivery is almost always cheaper and saves you carrying a ton of stone by hand.
Most landscape suppliers sell bulk in half-yard steps. A half-ton pickup can safely carry about one ton, so a few yards of stone usually means delivery by dump truck.
Common questions
How many tons are in a yard of gravel?
Between about 1.3 and 1.5 tons for most gravel. Clean crushed stone and pea gravel sit near 1.35 to 1.4 tons per cubic yard. Road base is heavier once you allow for compaction.
How much area does a ton of gravel cover?
One ton of 3/4" crushed stone is about 20 cubic feet. At 2 inches deep that covers about 120 square feet. At 4 inches it covers about 60 square feet.
How much gravel do I need for a driveway?
A 12 × 50 ft driveway with a 3 in top layer of crushed stone works out to 5.6 cubic yards, or 7.5 tons. With 10% extra, order about 6.1 yards (8.3 tons). If you are building it from scratch, add a 4 to 8 in compacted base of road base under that.
Why add compaction for road base?
Road base (3/4" minus) has fines that fill the gaps between stones when it is packed down. A loose yard compacts to roughly 85% of its volume, so you need about 15% more to reach the finished depth.
Should I order by the yard or the ton?
Order in whatever unit your supplier prices in. The estimate shows both, so you can match their price sheet.
Sources: typical loose densities from North American quarry and landscape supplier price sheets. For gravel surfaces and base materials, see Penn State's Center for Dirt and Gravel Road Studies. More on how we calculate.