Road base calculator for Rhode Island

A lane 100 feet long and 10 feet wide needs about 31 tons of road base at 6 inches of compacted depth. Tonnage builds fast on long runs, and free delivery is especially useful when hauling 30 tons can cost nearly as much as the stone. Road base is a graded crushed-stone-and-fines mix that weighs about 3,000 lb per cubic yard and packs into a firm layer beneath roads, driveways and equipment yards. Where the specification permits, use the same calculation for recycled crushed concrete base.

Lane calculations

1. For a lane, measure along its centerline and calculate from the average width. Pads use a straightforward length-by-width measurement.
2. For light residential areas, use 4 inches compacted. Allow 6 for regular traffic and delivery trucks, or 8-12 where subgrades are soft or equipment will sit.
3. Find yards by dividing cubic feet by 27, then multiply by 1.5 for tons and add 10% for compaction.

Lane coverage and tonnage

Building a lane for freeze-thaw seasons

• Clear off topsoil and other organic material before installing the base. Putting stone on topsoil lets mud push up through the aggregate, regardless of how deep the layer is.
• Lay woven geotextile over soft or wet ground before placing stone. It is an economical way to add support beneath a lane.
• Keep each layer at 4 inches or less, then roll it tight before adding another.
• Set a 2-3% crown from the middle toward each side so rainfall drains off the surface instead of entering the base.
• For a neat surface with less dust, finish with #57 or driveway gravel.
• Putting out 20-plus tons by hand can take up a week. Plan on a tractor with a box blade or a skid steer to handle the work in an afternoon.

Example: a 100-foot farm lane

For a stretch one hundred feet long and ten feet wide at 6 inches, 1,000 x 0.5 = 500 cubic feet = 18.5 cubic yards. Figure about 28 tons, or 30-31 after the allowance. It comes in two tandem loads, so arrange for separate unloading spots along the lane instead of leaving one large pile at the entrance. That makes spreading easier, especially where a long run or small lot leaves little room to move material.

Pads for RVs, containers, and equipment

For pads, use the same math but choose depth based on axle weight, not the calendar. At 6 inches compacted, a 12 x 40 RV pad needs about 12 tons. An equipment yard measuring 20 x 40 at 8 inches takes 27. Since shipping containers put their weight on four corners, use a full 8 inches plus fabric beneath a container pad, even where the ground seems decent, to help prevent corner settling after freeze-thaw.

Using crushed concrete for road base

Recycled concrete base can compact and support weight much like virgin road base, often at a lower cost. Some county specifications call for virgin aggregate, so confirm that before making the change. It works well for private pads and lanes. Use the same calculation: 1.5 tons per yard, with the same lift depth and crown.

Road base by ton and lane

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