Calculators / Pea gravel
Rounded, small, loose
Pea gravel calculator
For paths, patios, play areas and drainage. Rounded stone spreads easily and moves easily — depth matters more here than with crushed rock.
How deep, by project
| Project | Depth | Notes |
|---|---|---|
| Walking path | 2 in | Over fabric, with a solid edge. Without an edge it will be in your lawn by spring. |
| Patio or seating area | 2–3 in | On a compacted base. Loose stone over bare soil will rut under chair legs. |
| Dog run or play area | 3 in | Rounded stone is kind on paws but will be tracked indoors. |
| Drainage backfill | Trench depth | Use washed pea gravel with no fines so water moves freely. |
| Between pavers or stepping stones | 1–2 in | Just enough to sit level with the stone surface. |
Shallow is the whole trick
Pea gravel is rounded, so it does not interlock. Every extra inch of depth makes the surface less stable, not more durable. Two inches over a firm, compacted base walks better than four inches over soft ground and uses half the material.
That also means you should never rely on pea gravel as a structural layer. If the ground under it moves, the stone follows. Compact the subgrade, or lay a crushed-stone base first and use pea gravel only as the visible top.
Edging is not optional
The single most common pea gravel complaint is that it migrates. Steel, aluminium or composite edging set slightly proud of the finished stone level solves it. Plastic corrugated edging pinned into soft soil does not.
Budget for edging in the same trip. It is far more annoying to retrofit once the stone is spread.
Buying it
Under about a cubic yard, bags are usually the sane choice — a cubic yard is 54 half-cubic-foot bags, and each one weighs 50 pounds. Above that, order bulk by the ton and have it dropped as close to the work as the truck can reach.
Ask for washed pea gravel if it is going anywhere near drainage. Unwashed stone carries fines that clog the voids you are relying on.
Common questions
How deep should pea gravel be?
Two inches for paths and patios, three at most for play areas. Deeper layers shift underfoot and feel unstable because the stone is rounded rather than angular.
How many bags of pea gravel in a cubic yard?
Fifty-four bags of the common 0.5-cubic-foot (50 lb) size. That is 2,700 pounds, so it is also about 1.35 tons.
Can you use pea gravel on a driveway?
It is a poor choice. Rounded stone will not lock together and gets pushed into ridges by tyres. Use angular crushed stone for the driving surface and keep pea gravel for paths and beds.
Does pea gravel need a base underneath?
For anything you will walk or sit on, yes. A compacted crushed-stone base 3 to 4 inches deep stops the pea gravel sinking into soil and keeps the surface level.
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