Choosing the Right Gravel for Outdoor Projects
Not all gravel behaves the same underfoot or under tires. Learn how pea gravel, crushed stone, river rock, and decomposed granite differ, where each one works best, and how to estimate the amount you need.
By the CalcAndPlan Editorial Team · Published · 3 min read
In this article
Angular stone locks, round stone rolls
The biggest difference between gravels is shape. Crushed stone has sharp, fractured faces that interlock when compacted, which makes it the backbone of driveways and paver bases. Rounded stones such as pea gravel and river rock roll against each other, so they feel softer underfoot but shift under tires and heavy traffic.
Matching gravel to the job
Think about what the surface needs to do before choosing a color.
- Driveways and parking pads: compactable crushed stone or road base, often topped with a finer crushed layer
- Garden paths: pea gravel or decomposed granite for comfort, with solid edging to hold it in place
- Drainage trenches: clean, washed angular stone that leaves open spaces for water
- Decorative beds: river rock or colored stone, usually over fabric
Volume first, weight second
Measure the area and depth to get cubic yards. Many quarries sell by the ton, so you also need the density of the specific stone. That number varies by rock type, size, and moisture, so ask your supplier. Typical planning values fall around 1.3 to 1.5 tons per cubic yard, but treat those as a rough check, not a quote.
Plan for compaction and edges
Compacted base layers settle, and loose surface gravel migrates into lawns without a border. Budget a little extra stone for compaction, and add edging to the shopping list for any path.
Size matters as much as type
Gravel is graded by size. Smaller stone gives a smoother walking surface; larger stone drains faster and stays put better under weight. Suppliers often use local names or numbers for their sizes, so describe your project when you call and ask what they recommend. Bring a photo of what you want the finished surface to look like.
“Fines” — the dust and small particles mixed into crusher run and road base — help a base layer compact into a firm surface. Washed stone has the fines removed, which makes it better for drainage but less stable on its own.
Planning a gravel area that lasts
Most gravel problems come from what’s underneath, not the stone itself. Remove sod and soft topsoil, slope the area slightly so water runs off, and compact the subgrade before adding stone. Install edging before the gravel goes in.
Expect to rake gravel paths occasionally and add a thin top layer every few years as stone works into the soil or gets carried off on shoes and tires.
Worked example: a pea gravel garden path
- Path: 40 ft long × 3 ft wide, 3 in deep
- Volume: 40 × 3 × 0.25 = 30 cu ft = 1.11 cu yd
- Supplier quotes a density of 1.4 tons per cu yd
- Weight: 1.11 × 1.4 = 1.56 tons
- With 10% extra: about 1.22 cu yd or 1.7 tons
Order roughly 1.2 cubic yards — about 1.7 tons at the supplier’s stated density.
Helpful tips
Pro tips
- Ask whether the yard sells by the ton or the yard before you calculate, so your number matches their price list.
- Choose edging before ordering pea gravel or river rock; round stones migrate without a firm border.
- For anything that carries vehicles, use compactable angular stone for the base, even if the top layer is decorative.
Frequently asked questions
Is pea gravel good for driveways?
On its own, it tends to shift and rut under tires. Driveways usually use compactable crushed stone, sometimes with a decorative top layer.
Do I need landscape fabric under gravel?
It’s commonly used under paths and decorative beds to separate stone from soil. Driveway designs vary, so follow your supplier’s or contractor’s recommendation.
The bottom line
Pick gravel by what the surface needs to do, then calculate the volume and convert to weight using your supplier’s density. Budget a little extra for compaction and add edging to the list.
Further reading
General information for planning. Conditions vary by region, site, and product — check product labels and local guidance.