Road base calculator for Washington

At 6 inches after compaction, a lane 100 feet long and 10 feet across takes about 31 tons of road base. Long runs consume material fast, and free delivery is especially helpful when 30 tons of hauling can approach the stone cost. Road base combines graded crushed rock with fines and weighs about 3,000 lb per cubic yard. Once compacted, it creates a firm layer for equipment yards, roads, and driveways. Where specifications permit, recycled crushed concrete base uses this same calculation.

Lane quantity math

1. For a lane, measure its centerline length and calculate from the average width. A pad uses length multiplied by width.
2. Use 4 inches compacted for light residential ground, 6 for regular traffic and delivery trucks, and 8-12 where subgrade is soft or equipment will sit.
3. Divide cubic feet by 27 to find yards; multiply by 1.5 for tons; retain +10% for compaction.

Lane coverage and tonnage

Build a lane for the wet season

• Take out organic material before placing stone. Topsoil beneath base will push mud into the rock, regardless of how deep the layer is.
• Lay woven geotextile ahead of the stone on wet or yielding subgrade. For a lane, it is a low-cost way to build in strength.
• Place material in 4 inches or smaller lifts, rolling each one before placing the next.
• Build a 2-3% crown outward from the centerline, directing rain to each side rather than letting it enter the base.
• For a neat, dust-free driving surface, finish with #57 or driveway gravel.
• Hand-spreading 20-plus tons can consume a week. A box blade on a tractor or a skid steer can handle it in an afternoon, so account for the machine.

Farm lane example at 100 feet

For one hundred by ten feet at 6 inches, the calculation is 1,000 x 0.5 = 500 cubic feet = 18.5 cubic yards, or about 28 tons. With the allowance, that becomes 30-31. It comes in two tandem loads, so arrange two drop points along the lane instead of one large pile at the entrance. Separate piles on farm lanes can limit the uphill material handling.

Equipment, container, and RV pads

Pad calculations follow the same method, but select depth by axle load rather than season. An RV pad measuring 12 x 40 at 6 inches compacted takes about 12 tons. A 20 x 40 equipment yard at 8 inches requires 27. Container weight bears on four corners, so use a full 8 inches plus fabric for container pads, even where ground appears sound, to limit corner settlement by spring.

Using crushed concrete for road base

Recycled concrete base compacts and supports loads similarly to virgin road base, often at a lower cost. Review county specifications before making the change, since some call for virgin aggregate. It can be used for private pads and lanes. Quantity calculations remain unchanged: 1.5 tons per yard, the same lifts, and the same crown.

Road base quantities by ton and lane

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