Key Takeaways
- Pea gravel is smooth and rounded; crushed stone is angular and interlocking
- Pea gravel works for decorative beds, play areas, and pool surrounds
- Crushed stone works for driveways, parking areas, and under concrete or pavers
- Crusher run and washed crushed stone are not interchangeable for base layers
- Both use the same calculation: area times depth gives volume, volume times density gives weight
This calculation follows standard aggregate industry methodology.
Cubic yard is a unit of volume equal to a cube measuring 3 feet on each side, commonly used in the US for ordering gravel and other aggregates.
Density in gravel calculations refers to the weight of material per unit volume, typically measured in tons per cubic yard or tonnes per cubic metre.
The short version: pea gravel is smooth and rounded, so it feels good underfoot and reads as decorative, but it never locks together and it will migrate off a slope. Crushed stone is angular, so it interlocks and stays put under load, but it is not something you walk on barefoot. Most of the time the project has already decided which one you need before cost enters the conversation.
What actually differs
The shape, not the size. Pea gravel is naturally tumbled, typically by water, which rounds off every edge. Crushed stone is mechanically broken, which leaves every piece with flat faces and sharp corners. Two materials can be the exact same size and still behave completely differently because of that one fact.
Rounded pieces roll past each other. That’s what makes pea gravel comfortable to walk on and pleasant to look at, and it’s also exactly why it can’t be compacted into a stable base and why it drifts downhill or toward a door on any real gradient. Angular pieces wedge against each other. That’s what makes crushed stone lock into a firm surface under a car or a foot traffic path, and it’s also why nobody puts it in a play area or a barefoot path.
Where pea gravel wins
Decorative beds and borders. It looks finished, comes in a narrow colour range per source, and reads as intentional rather than utilitarian.
Play areas and around pools. Smooth, no sharp edges, comfortable bare skin contact. The trade-off is it needs a proper containing edge and it will still track outside that edge over time as feet move it.
Aquariums and decorative accents. Where load bearing was never the question.
Where crushed stone wins
Anything driven or walked on repeatedly. Driveways, parking areas, paths that see regular foot traffic. The interlock is what keeps the surface from rutting.
Anything that has to drain and stay put. French drains, backfill behind a retaining wall. The angular voids let water through while the pieces themselves don’t wash away the way loose round stone can.
Under concrete or pavers. A base layer has to compact into something solid, which is exactly what rounded stone cannot do.
The one thing that catches people out
Crusher run and washed crushed stone are not interchangeable with each other, and that distinction matters more than pea gravel versus crushed stone does for a base layer specifically. Crusher run keeps its fine particles, so it binds and compacts. Washed crushed stone like #57 has those fines removed, so it drains but never really locks solid. Neither is “better” than pea gravel in the abstract; they’re solving a different problem than pea gravel is.
Working out the quantity
Both materials run through the same calculation once you’ve picked one: area times depth gives a volume, volume times density gives a weight. The densities differ a little (pea gravel is typically around 1.35 tons per cubic yard, most crushed stone closer to 1.4), which is exactly the kind of detail the pea gravel calculator and the crushed stone calculator handle for you, each preset to the material’s own typical density and each editable if your supplier quotes something different.
Editorial note: This article is reviewed for accuracy and updated regularly. All calculations use standard industry formulas. For the latest density figures, consult your gravel supplier directly.
Frequently asked questions
Which is cheaper, pea gravel or crushed stone?
Crushed stone is typically cheaper per ton than pea gravel because it requires less processing. However, the total cost depends on your project: crushed stone may need a base layer underneath, while pea gravel can sometimes be used alone for decorative applications. Get both quotes and factor in delivery.
Can I use pea gravel for a driveway?
Pea gravel is not recommended for driveways. Its rounded shape means it will shift and migrate under vehicle traffic, creating ruts and an uneven surface. Use crushed stone or crusher run for driveway surfaces and base layers.
What is the difference between crushed stone and crusher run?
Crushed stone has been washed to remove fine particles, so it drains well but does not compact tightly. Crusher run keeps its fines, allowing it to compact into a solid base. For a driveway, you typically use crusher run as the base and crushed stone as the surface layer.
How do I calculate how much material I need?
Measure the area in square feet, multiply by the depth in feet to get cubic feet, then divide by 27 to get cubic yards. Multiply by the material’s density to get tons. The gravel calculator does this automatically for any area and material.