River Rock Sizes
From pea gravel to 3-5" stone — what each river rock size is best for, how deep to lay it, and how far it goes. Pick a size, then work out the amount with the river rock calculator.
River rock is sold by size grade, and choosing the right one is mostly about the job and the look. Smaller stone gives a fine, tidy surface but scatters and can track underfoot; larger stone reads bold and natural and handles water flow, but needs to be laid deeper. The table below maps each common size to its best use, the depth it should be laid at, and roughly how far a ton goes.
River rock size comparison
| Size | Best for | Depth | Coverage | Notes |
|---|---|---|---|---|
| Pea gravel (1/4"–3/8") | Paths, fill, fine décor | 2" | ~120 sq ft/ton | Smooth and small; scatters underfoot. |
| 3/4" river rock | Drainage, French drains, beds | 2" | ~120 sq ft/ton | Great open flow for drainage. |
| 1"–3" river rock | Ground cover, beds, dry creek beds | 3" | ~80 sq ft/ton | The most popular all-purpose size. |
| 2" river rock | Ground cover, borders | 3" | ~80 sq ft/ton | Tidy mid-size look. |
| 3"–5" river rock | Accent, drainage, erosion control | 4" | ~60 sq ft/ton | Large; needs deeper placement. |
| Mexican beach pebble | Modern, high-end beds & rings | 2"–3" | ~90–110 sq ft/ton | Naturally smooth, water-tumbled premium stone. |
Coverage figures assume generic river rock at about 100 lb/ft³ and the depth shown. For your exact numbers, the calculator lets you pick the rock type and depth.
The key rule: size dictates depth
The most common mistake is laying large stone too thin. As a rule, your depth should be at least one stone-diameter so the soil or fabric underneath never shows through. That's why 3"–5" rock needs around 4 inches of depth while pea gravel looks complete at 2 inches. Going deeper than necessary just wastes stone — and laying too shallow means buying more later to patch bare spots. Our how-to guide walks through the full depth-and-volume method.
A note on large river rock (3" and up)
Large river rock behaves differently from smaller stone. Once you get above about 3 inches, the stones are usually laid in a single layer rather than piled deep, and suppliers typically sell them by the ton rather than the cubic yard. As a rough coverage guide, plan on about 50 square feet per ton for 3"–6" rock and roughly 25 square feet per ton for stone over 6". If you're using large rock, enter your real single-layer depth in the calculator (often close to the stone's diameter) rather than a standard 2–4 inches.
Which size for which project
Quick recommendations by project:
- Drainage & French drains: 3/4" washed rock — see river rock for drainage.
- Ground cover & beds: 1"–3" river rock, the all-purpose standard.
- Dry creek beds: a mix of 1"–3" surface stone with 3"–5" rock and accent boulders — see dry creek bed.
- Around trees: 1"–3" rock or smooth beach pebble — see river rock around trees.
- Modern, high-end beds: Mexican beach pebble for a polished finish.
Found your size? Get the amount.
Enter your area and depth and the calculator returns cubic yards, tons, and bags — plus bulk-vs-bagged cost.
Open the River Rock Calculator →Frequently asked questions
What size river rock is best?
1"–3" river rock is the most popular all-purpose size — large enough to stay in place and small enough to look tidy as ground cover. Use 3/4" for drainage, 3"–5" for accents and erosion control, and beach pebble for a modern, polished look.
What is 1-3 inch river rock used for?
1"–3" river rock is used for ground cover in beds, around trees, along borders, and as the surface of dry creek beds. It is the standard landscaping size because it resists scattering yet still reads as natural stone.
How deep should river rock be?
Lay river rock at least as deep as one stone is wide so the ground does not show through. Use about 2 inches for small stone like pea gravel, 3 inches for 1"–3" rock, and 4 inches for larger 3"–5" rock.
What is the most popular size of river rock?
The 1"–3" grade is the most popular size of river rock for landscaping. It works for beds, ground cover, tree rings, and dry creek beds, which is why most suppliers stock it as their standard decorative stone.