What counts as pea gravel
Pea gravel is small, rounded stone named for its size; there is no standard grade.
There is no ASTM or AASHTO size called "pea gravel". The name is used for small, rounded stone; UC Master Gardeners give it as an example of river-run gravel.[1] For a sense of size, one manufacturer's bagged all-purpose gravel has a top size of about 3/8 in (9.5 mm),[4] and the RHS describes fine gravel grades as 10 mm or less.[5]
Because the stones are rounded, pea gravel never packs down completely.[1] It stays loose and free-draining rather than forming a firm surface.
How deep to lay pea gravel
Lay pea gravel at least 2 inches deep for a path, 2–3 inches as a mulch and 4 inches to suppress weeds.
| Use | Depth | Source |
|---|---|---|
| Garden path | 2 in minimum; 4 in if stepping stones are set into it | [1] |
| Gravel mulch around plants | 2–3 in | [3] |
| Gravel mulch to suppress weeds | 4 in (stones about ½ in or smaller) | [2] |
Pea gravel is small enough to work as a mulch; Colorado State notes that stones larger than about half an inch do not.[2] Larger decorative stone is covered by the river rock calculator, and other uses in the gravel depth guide.
Bags of pea gravel for common patio sizes
A 10 × 10 ft area 3 inches deep takes 50 bags of 0.5 cu ft.
One major manufacturer sells its pea pebbles in 0.5 cu ft bags,[6] 54 to the cubic yard.
| Patio (ft) | 2 in | 3 in | 4 in |
|---|---|---|---|
| 8 × 8 | 22 (0.4 yd³) | 32 (0.59 yd³) | 43 (0.79 yd³) |
| 10 × 10 | 34 (0.62 yd³) | 50 (0.93 yd³) | 67 (1.23 yd³) |
| 12 × 12 | 48 (0.89 yd³) | 72 (1.33 yd³) | 96 (1.78 yd³) |
| 12 × 16 | 64 (1.19 yd³) | 96 (1.78 yd³) | 128 (2.37 yd³) |
| 16 × 20 | 107 (1.98 yd³) | 160 (2.96 yd³) | 214 (3.95 yd³) |
Past a cubic yard or two, the bag count gets large: a 12 × 16 ft patio at 3 inches is 96 bags. Compare with a bulk delivery quoted by the yard or ton.
How much does a yard of pea gravel weigh?
About 2,700–3,100 lb (1.35–1.55 US tons) per loose cubic yard, using the general gravel range.
We could not find a primary source that gives pea gravel its own density, so this site uses the general loose gravel range: 2,700–3,100 lb per cubic yard from dry to wet,[7] or 1.35–1.55 US tons. A cubic yard of pea gravel for the default 12 × 12 ft patio at 3 inches (1.33 yd³) weighs roughly 1.8–2.1 tons.
Buying by weightIf your supplier quotes tons, the tons to cubic yards converter turns that into a volume, and the gravel calculator covers crushed stone.
Frequently asked questions
How many bags of pea gravel do I need?
Work out cubic feet (square feet × depth in inches ÷ 12), then multiply by 2 for 0.5 cu ft bags. A 10 × 10 ft area at 3 inches is 25 cu ft, or 50 bags.
How deep should pea gravel be for a patio?
Published guidance for gravel paths gives 2 inches as a practical minimum, and 4 inches when stepping stones or pavers are set into it.[1]
How much area does a yard of pea gravel cover?
162 sq ft at 2 inches, 108 sq ft at 3 inches and 81 sq ft at 4 inches.
Does pea gravel compact?
Not fully. Rounded, river-run gravel never packs down completely, unlike angular crushed stone.[1]