Key Takeaways
- Crusher run is crushed stone with fine particles left in, not washed or screened out
- The fines allow it to bind together and compact into a firm, load-bearing layer
- It is the standard base material for driveways, patios, and paver installations
- Density is around 1.5 tons per cubic yard, heavier than washed stone due to the fines
- Not suitable for drainage applications where open voids are needed
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.
Crusher run is crushed stone with its fine particles left in, rather than washed or screened out. That single fact is the whole reason it exists as a distinct product: the fines are what let it bind together and compact into a firm, load-bearing layer, which is exactly the job a driveway or a patio base needs done and a clean washed stone cannot do on its own.
What’s actually in it
A mix of stone fragments in a range of sizes, typically down to dust, all from the same parent rock. Nothing is added; nothing is taken away after crushing. That graded mix, big pieces and small dust together, is what a plain single-size washed stone doesn’t have.
Why the fines matter
Picture the difference between a jar of marbles and a jar of marbles packed with sand in the gaps. The marbles alone roll past each other under any load. Fill the spaces between them and the whole thing locks rigid. That’s the mechanism. In washed stone like #57, the voids between the pieces stay open, which is exactly what you want for drainage and exactly what you don’t want in something that has to carry a car without rutting.
What it’s actually used for
The base layer under almost anything structural. Driveways, patios, paver installations, shed pads. If a gravel calculator on this site defaults a base layer to a material, it’s very likely crusher run, and that’s not an accident.
Not for drainage. This is the one place people get it backwards, usually because it’s the cheaper material on the yard’s price list. A french drain or a drainage layer needs the opposite property crusher run has: open voids that let water through. Put crusher run in a drain and it packs solid and stops draining, which is the one thing the drain was dug to prevent. Use a washed, clean stone there instead.
Not as a finished walking surface, generally. It compacts hard and looks utilitarian rather than finished, which is why a driveway often gets a washed stone or decorative layer on top of a crusher run base rather than leaving the crusher run exposed.
Density and what that means for quantity
Crusher run typically runs a little heavier than a washed stone of similar size, around 1.5 tons per cubic yard against roughly 1.4 for something like #57, because those fines are filling space that would otherwise be air. It’s a small difference per cubic yard but it adds up on a full driveway base, which is exactly why the driveway calculator treats each layer as its own material and its own density rather than averaging the whole build into one number. The crushed stone calculator covers crusher run alongside the numbered washed grades if you want to compare them directly.
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
Is crusher run the same as gravel?
Crusher run is a type of gravel, but not all gravel is crusher run. Crusher run specifically refers to crushed stone that retains its fine particles, which allows it to compact. Regular gravel may be washed or screened, removing the fines that make crusher run bind together.
How deep should crusher run be for a driveway?
For a residential driveway, 4 to 6 inches of compacted crusher run is typical for the base layer. On soft or clay soil, you may need 6 to 8 inches. The driveway calculator helps you determine the right depth based on your specific conditions.
Can crusher run be used for drainage?
No. Crusher run compacts solid and stops water from flowing through. For drainage applications like French drains, use a washed, clean stone with open voids instead. Crusher run in a drain will pack tight and defeat the purpose.
How much does crusher run weigh per cubic yard?
Crusher run typically weighs around 1.5 tons per cubic yard, which is heavier than most washed stones due to the fine particles filling the voids. The exact weight depends on the parent rock and moisture content.