Pea gravel is the smooth, rounded stone you will have seen on garden paths, patios and play areas. The stones are small — roughly pea-sized, as the name suggests — and because they are rounded rather than angular, they are comfortable to walk on and easy to rake level. Like any gravel, pea gravel is sold by the ton or by the bag, and the amount you need comes from one simple calculation: the area you want to cover multiplied by the depth. The difference from driveway gravel is that pea gravel goes down thinner, so the depth you choose matters more than any other number in the maths.
This guide works through the calculation step by step — the right depth for each job, how much area a ton or a bag covers, and a full worked example. If you would rather skip the arithmetic, the free Gravel Calculator does it for you: enter a length, width and depth and it returns tons, cubic yards and bags.
How deep should pea gravel be?
Depth is the one decision you have to make before any of the numbers work. Pea gravel does not lock together the way angular stone does, so it spreads and settles differently. Use these depths as your starting point:
- Paths and patios: 2–3 in. Two inches gives a firm, tidy finish on solid ground; go to 3 in where the soil underneath is soft.
- Around stepping stones: 2 in is plenty — the stones take the weight and the gravel only fills the gaps.
- Play areas: 3 in or more, laid over a weed membrane, so there is some cushion if a child falls.
- Garden beds and decorative areas: 2 in covers the soil, keeps the finish neat and holds back most weeds.
Whichever depth you choose, pea gravel needs edging, and it is worth being honest about why. The stones are round, so they roll and migrate underfoot instead of staying where you spread them — an unedged pea gravel path will slowly spread itself across your lawn and beds. Fit a firm edge of brick, stone, timber or metal strip before you start, and expect to rake the surface level again from time to time. That bit of movement is the trade-off for how good pea gravel looks and how comfortable it feels underfoot.
Coverage: how much a ton and a bag actually cover
Once the depth is settled, coverage turns your area into a weight you can order. Pea gravel weighs much the same as other gravel of a similar size, and the numbers work out like this:
| Amount | Covers at 2 in deep | Covers at 3 in deep |
|---|---|---|
| 1 ton (bulk) | About 115 sq ft | About 77 sq ft |
| One 0.5 cu ft bag | About 3 sq ft | About 2 sq ft |
Look at what the depth does to those figures: moving from 2 in to 3 in uses half as much stone again over the same area. That is why guessing the depth is the most expensive mistake you can make with pea gravel — far worse than being a few percent out on the area. If you want to test your own measurements against these rates, run the same figures through the Gravel Calculator and compare the tons it gives you.
Worked example: a garden path
Say you are laying a path 12 ft long and 3 ft wide, at 3 in deep. The sums go like this:
- Area: 12 × 3 = 36 sq ft.
- Volume: 36 sq ft × 0.25 ft (3 in expressed in feet) = 9 cu ft.
- Cubic yards: 9 ÷ 27 = 0.33 yd³.
- Tons: at pea gravel’s usual density, 9 cu ft comes to roughly 0.47 tons.
So the sensible order is half a ton in bulk — one bulk bag or a small loose load — which leaves you a little spare for the patches that settle. If bags are easier to handle, the same job takes 18 bags (9 cu ft ÷ 0.5 cu ft per bag), though bulk usually works out cheaper per ton. And if the jump between cubic feet and cubic yards is where you lose track, the Cubic Yard Calculator does that single conversion on its own.
Buying tips
- Add 5–10% to your order. Pea gravel settles into the ground beneath it, and a few barrowfuls always escape along the way.
- Check the stone size before you order: 3/8 in is the standard pea gravel. Larger rounded stone behaves more like decorative gravel and wants a little more depth.
- Lay a weed membrane underneath on paths and play areas. As well as stopping weeds, it slows the stone sinking into soft soil.
- If the colour looks dull when the stone arrives, hose it down — pea gravel’s real colour only shows when it is wet and the quarry dust has rinsed off.
Frequently asked questions
How deep should pea gravel be?
For paths and patios, 2–3 in is the sweet spot: 2 in on firm ground and 3 in where the base is soft. Around stepping stones 2 in is enough, and play areas want 3 in or more over a weed membrane.
How much area does a ton of pea gravel cover?
About 115 sq ft at 2 in deep, and about 77 sq ft at 3 in deep. In bags, one 0.5 cu ft bag covers roughly 3 sq ft at 2 in.
Does pea gravel need edging?
Yes. Pea gravel is round, so it rolls and migrates underfoot instead of locking together. A firm edge of brick, stone, timber or metal strip keeps it where you put it.
Pea gravel or crushed gravel — which is better?
They suit different jobs. Pea gravel is smooth, decorative and comfortable underfoot, but it shifts. Crushed gravel is angular, locks together and stays put, which makes it the better choice for driveways and anywhere vehicles drive.
Estimates only — depths and coverage vary a little with stone size.