Crusher Run Calculator: Sizing a Base That Is Not CR-6
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Ask for base stone in two Maryland yards and you can come away with two different products. CR-6 is the designation this state uses for dense-graded driveway and road base; Crusher Run sits beside it in the catalogue as its own listing, a compacting blend of crushed stone and fines ordered for much the same work. The crusher run calculator will not choose between them for you. What it will do is turn a footprint and a finished depth into tons, and the depth you type is what decides whether a shed pad on Piedmont silt is still flat after its first winter.
Pads, lanes and paver sub-bases: the depth each one is built to
Start here rather than at the form, because depth moves the answer further than any other entry.
| What you are building | Compacted depth to plan | The reason for it |
|---|---|---|
| Paver or slab sub-base | 4 inches, placed in 2-inch lifts | Thin lifts roll properly; one thick lift does not |
| Drive base under a wearing course | 4 to 6 inches | Take the 6 where the subgrade is clay or stays wet |
| Shed, hot tub or equipment pad | 4 inches over stripped ground, 6 on soft ground | Piedmont silt softens when it is saturated and wants the extra |
| Truck, trailer or turnaround areas | 6 to 8 inches | Point loads from a loaded axle spread through depth |
| Rural lane run as the driving surface | 4 to 6 inches, regraded every 2 to 4 years | It binds into a crust, then dusts in a dry July |
Every figure in that column is the depth after rolling, not the depth of the loose pile you tip out. This page's own guidance is that loose material tightens by 10 to 15 percent as it is compacted, so a layer raked out at 4 inches finishes nearer three and a half.
Frost runs deeper than any base you will build in this state: roughly 30 inches under most county codes, 36 in Garrett and Allegany, 24 in some Eastern Shore counties. Depth in the table above is about spreading load and shedding water, not about reaching below the frost line.
Entering a Westminster lane at the depth it will finish at
The form takes a shape first. Rectangle covers a pad or a straight run. Circle asks for a diameter across the widest point. Multiple areas holds up to five at once, which is what a drive with a turning bulb at the end actually is.
Lengths, widths and diameters go in as feet. Depth goes in as inches, anywhere from 0.25 to 24, and it should be your compacted target from the table. Pick the material next, since that choice is what sets the weight the tool converts with, then leave the box marked add 10 percent extra for compaction and spillage ticked, or untick it. Three figures come back at once, cubic yards, tons and cubic feet, and the result can be emailed over as a written quote rather than copied off the screen by hand.
Running a shed pad, a farm lane and an equipment pad through the form
All three are invented for this page, not jobs anyone has ordered.
A shed pad, 13 by 17 feet, at 4 inches compacted. That is 221 square feet. Four inches is a third of a foot, so the volume is 73.67 cubic feet; divided by 27 it comes to 2.73 cubic yards. At roughly 1.50 tons per cubic yard the order is about 4.09 tons, and with the 10 percent box ticked it reads 3.00 cubic yards, near enough 4.50 tons.
A lane, 105 feet by 10 feet, at 6 inches. Area 1,050 square feet, half a foot deep, giving 525 cubic feet. Divided by 27 that is 19.44 cubic yards, or about 29.2 tons. The 10 percent allowance takes it to 32.1 tons.
An equipment pad, 24 by 14 feet, at 8 inches over soft ground. Area 336 square feet at two thirds of a foot is 224 cubic feet, which is 8.30 cubic yards and roughly 12.4 tons. With the allowance, about 13.6 tons. A pad that size is a long weekend of spreading by hand and an afternoon with a machine.
Where the 3,000 pound yard comes from, and what CR-6 shares with it
The fines are the reason this material weighs what it does. Screened stone leaves voids between the pieces; a blend with dust in it fills them, so the same cubic yard carries more.
| What you might order for the same drive | Published weight per cubic yard | Tons per yard |
|---|---|---|
| Crusher run, and the CR-6 that goes under most drives here | about 3,000 lb | 1.50 |
| #57 stone or 3/4 inch stone, spread over the top as the wearing layer | about 2,800 lb | 1.40 |
| Stone dust, screeded thin under flagstone | about 2,900 lb | 1.45 |
Those are this site's own published figures and all of them are approximate. Both base products sit on the same line, so switching between Crusher Run and CR-6 changes the listing you buy from, not the tonnage you worked out.
One thing this material will not do is drain. The dust that makes it bind also holds water, so a French drain or a wall backfill wants clean washed stone instead, sized on the stone calculator. If the job is a patio rather than a pad, the paver base calculator handles the overhang past the paver edge that this page does not.
The extra half ton that fills ruts after the Garrett County thaw
Round the tonnage up rather than down. A pad that comes out at 4.50 tons is a 5 ton order, and the difference is a few wheelbarrows you will want anyway.
Compaction is where the surplus goes. Build in 2-inch lifts, mist each one lightly before rolling, and expect the finished level to sit below where the loose material started. Base work runs spring through late fall across the state; frozen or saturated ground will not compact at all, and that window stays shut longest on the Garrett plateau. Keep the last wheelbarrow-load under a tarp for the ruts that show up at the first thaw.
From the ton figure to a date on the order
Take the tonnage across to the product listing, set the quantity there and choose a delivery date. Delivery is arranged at checkout by ZIP code, and the delivery page covers what the truck needs at the other end. If the drive is being built in two layers, run the wearing course as its own calculation and add driveway gravel or a washed stone as a separate line.
Common questions
I have my tonnage. Which listing do I open to actually buy it?
Go to the Crusher Run page if you want this blend specifically, or the CR-6 listing if you are matching what a Maryland contractor has specified for the base. Both are sold by the ton and both convert at the same published weight, so the number you just worked out carries over unchanged. Set the quantity and the date on that page.
Where should the driver put 13 tons so I am not moving it twice?
Pick the spot before you order, and pick it uphill of the work if the ground slopes, because spreading downhill with a wheelbarrow is a great deal quicker. The ground under the pile needs to be firm enough for a loaded truck, with nothing overhead and room to back in and tip. If the pile has to land on a finished drive or apron, put a tarp down first, since the fines in this material stain.
The result gives me yards and tons together. Which one am I ordering in?
Tons, for this material. The cubic yard figure is the volume your excavation actually needs and it is worth writing down, because it is the number that tells you whether two jobs can share a load. Tons is what the listing is sold by, so that is the figure that goes into the quantity box.
Do I measure the depth of the loose stone or the depth after rolling?
After rolling, always. Every depth on this page is a compacted figure. If you dig out to 4 inches and order only enough loose material to fill 4 inches, the finished base ends up short once the plate compactor has been over it. Dig and order to the compacted target, then let the material sit proud before you roll it.
How do I get a figure for a round pad, such as a fire pit surround?
Switch to the circle setting and measure straight across the widest point for the diameter, not around the edge. A 9 foot circle covers about 64 square feet, and at 4 inches that is 21 cubic feet, or 0.79 cubic yards, roughly 1.2 tons. If a pit or a footing sits in the middle, calculate the full circle and take the middle off by hand rather than guessing at it.
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