Crusher Run Calculator — tons and cubic yards for a base layer
Work out the tonnage of crusher run or dense-graded aggregate base for a driveway, road or pad — using a density range that two separate state DOTs agree on.
Crusher run — also sold as dense-graded base, road base or 3/4 inch minus — is the compacted aggregate layer that carries a driveway or road. It is ordered by the ton, so the only hard question is the conversion from your area and depth.
This is the material we can source most confidently. The Wisconsin DOT research programme physically tested aggregate conversion factors across the state, and the Iowa DOT publishes a separate estimating density for Class "A" crushed stone. Two independent state transportation departments land within a few percent of each other, which is about as solid as bulk-material data gets.
We use the narrower research range rather than the wider band the same report gives for contract bidding, and we tell you that on the page. If you are pricing against a DOT specification, the bidding band is the one to use — and we say that too.
A worked example you can check by hand
A 20 ft × 10 ft area at 2 in deep,
with a 5% waste allowance:
We do not use a hidden "magic number". Here is the entire calculation:
volume = area × depth
volume_with_waste = volume × (1 + waste%)
weight = volume_with_waste × density
Why a range, not one number? Bulk material density changes with
moisture, gradation and compaction. Publishing a single figure would be falsely precise, so we publish
the range our sources support — and we show you exactly where each number comes from.
Why we state the state. This material is only published at one
placement state, so there is nothing to choose — but we say which one it is, because loose and compacted
material differ by 27–60% in volume and most calculators never tell you which they used.
Crusher run / dense-graded aggregate base, compacted
How we chose the typical value. WisDOT's research-recommended range for 3/4 in dense-graded base is 1.78–1.98 short ton/yd³; the midpoint is 1.88 t/yd³. We set the typical at 1.9 t/yd³ (= 140.7 lb/ft³), which is also exactly Iowa DOT's Class "A" crushed stone estimating value of 140 pcf. Two independent state DOTs agree.
Limits of this constant
Compacted in-place density. If you are ordering loose material by volume, the same tonnage occupies noticeably more volume — see the state selector.
WisDOT also publishes a wider statewide empirical band (1.75–2.10 t/yd³) used for contract bidding. We use the narrower research range and say so.
This calculator is only valid under these assumptions. If any of them do not match your project,
treat the result as a rough guide and get a quote from your supplier.
The area is treated as a rectangle, and the depth is the COMPACTED thickness of the finished base layer.
The material is a dense-graded crushed aggregate base (crusher run, road base, 3/4 inch minus, or similar) placed and compacted in layers.
You are compacting in lifts of 4 to 6 inches, as is normal practice. A single thick lift will not reach the density assumed here.
The aggregate is at the moisture content used by the source measurements; very wet stockpiles weigh more per cubic yard.
No allowance for geotextile, drainage, grading or the surface course on top.
Frequently asked questions
How many tons is a cubic yard of crusher run?
About 1.78 to 1.98 short tons per cubic yard compacted, with 1.9 as the working figure. That comes from Wisconsin DOT research on 3/4 inch dense-graded base, independently supported by Iowa DOT's 140 lb/ft³ estimating density for Class "A" crushed stone.
What is the difference between crusher run and clean stone?
Crusher run contains the fines from crushing as well as the stone, so it compacts into a firm, nearly impermeable layer — which is what you want for a base. Clean stone has the fines washed out, drains freely, and will not lock together, so it is used for drainage rather than load bearing. They also weigh differently, so do not swap one for the other without recalculating.
How thick should the base be under a driveway?
Four inches of compacted crusher run is the usual minimum for a domestic driveway over firm subgrade, 6 inches where the ground is soft or the vehicles are heavy, and 8 inches or more for regular lorry traffic. The base is compacted in lifts of 4 to 6 inches.
Why do different websites give different tonnages?
Because they use different densities, and usually do not tell you which. On the same volume we have seen published figures ranging from about 1.6 to 2.2 short tons per cubic yard — a spread of more than 35%. We show our range and our sources so you can judge it rather than guess.