Crusher Run Calculator for Camp Roads and Packed Pads

Dense glacial till holds water. Sand and gravel outwash sheds it. Plenty of New Hampshire lots have both, sometimes within a hundred feet of each other, and that difference decides the number you type into the depth box here.

Three readings to take before any arithmetic

Probe for ledge. Granite sits close to the surface across most of the state. Where the bar stops at 5 inches and the drawing said 8, the pad gets built up instead of dug down. The depth you enter is then the finished height above the rock, and the edges need shaping so water runs off rather than sits.

Squeeze a handful of subgrade. Till with a hardpan layer under it drains slowly. Stone placed on soft wet till works down into it and keeps going. That is the argument for the extra 2 inches of base, and for woven fabric underneath on the worst of it, which you would source from a landscape supplier rather than here.

Watch where the water sits in April. Thawed ground holds water above soil that is still frozen, so a run that looks firm in August can be pudding in mud season. Base across that line wants more depth than the same base on a dry river terrace.

Depth will not defeat frost. It reaches about 48 inches down south and 60 or more in the North Country, and no drive base goes anywhere near that. What keeps a surface from breaking up each spring is drainage underneath and honest compaction on the way in.

Compacted depth goes in the box, not loose depth

Crusher run tightens by something like a tenth to a seventh of its loose depth once a plate compactor or a loaded truck has been over it. Order to the depth you measured in the hole and the finished lane comes up shy.

So enter the depth you want after rolling:

The form takes a shape first. Rectangle for a lane or a pad, circle for a round turnaround, or multiple areas if the job is several pieces, up to five of them totaled together. Length, width and diameter are in feet. Depth is in inches and accepts anything from 0.25 up to 24. Then the material select, since the weight rides on that choice.

There is a box that adds 10% for compaction and spillage, ticked by default. Leave it ticked here. Crusher run is placed to be squashed.

Results come back as cubic yards, tons and cubic feet. Email my quote sends the figures in writing.

Yards first, then 1.5 tons on each one

The tool does this, but it is worth being able to check it.

Cubic yards = length ft x width ft x depth in, divided by 12, divided by 27.

Tons = cubic yards x 1.50.

That 1.50 comes from the published weight for this family: about 3,000 lb in a cubic yard, fines included. It is the heaviest of the ordinary base materials sold here, heavier than clean stone, because the dust fills the gaps that clean stone leaves open. The same row covers crushed gravel, the base course most New Hampshire contractors specify, and which NHDOT lists as Item 304.3. That item number is how the material is described locally, not a certification held here.

The binding is also why this stone stays out of a French drain. Fines hold water. For a drain, use drain rock or clean #57 stone.

Widening a turnaround on a camp road

Hypothetical. A 70 foot stretch of camp road gets widened by 10 feet so a delivery truck can swing without dropping a wheel off the shoulder. Finished depth 6 inches.

• 70 x 10 = 700 sq ft
• 700 x 0.5 ft = 350 cu ft
• 350 / 27 = 12.96 cu yd
• 12.96 x 1.50 = 19.44 tons
• With the 10% box: 14.26 cu yd, 21.38 tons

Place it in two 3 inch lifts and compact each one. Two lifts hold up where one thick layer ruts.

A parking apron at the top of a sloped drive

Hypothetical. The drive climbs, and everyone parks on the flat at the top. Make that 12 by 20 at 4 inches compacted.

• 12 x 20 = 240 sq ft
• 240 x 0.333 ft = 80 cu ft
• 80 / 27 = 2.96 cu yd
• 2.96 x 1.50 = 4.44 tons
• With the 10% box: 3.26 cu yd, 4.88 tons

Mist each lift before the compactor goes over it. Damp material locks together. Bone dry material just rearranges itself.

Where the slack actually goes

The 10% is not a margin on your tape. It covers what compaction takes out of the load and what ends up in the grass either side of the pile.

Slack sits on top of that, and it goes in the direction of more. Round up. Half a ton left over patches potholes in the fall, while a short load means moving a pile twice.

Keep a wheelbarrow of it back for exactly that. Road crews do.

Once the tonnage looks right, open the crusher run page, set a quantity and a date, and delivery is arranged at checkout from your ZIP code. The truck wants firm ground and clear room to tip. If the last stretch of road is soft, say so through the contact page before the load is booked. Flatwork bases carry a border allowance of their own, handled in the paver base tool, and everything else has its own entry among all the calculators.

Common questions

Related calculators