Road base calculator for Iowa

At 100 feet long, 10 feet wide, and 6 inches after compaction, a lane takes about 31 tons of road base. Lane quantities can grow quickly, making free delivery especially relevant when moving 30 tons can otherwise cost nearly as much as the stone. Road base combines graded crushed stone with fines, weighing about 3,000 lb per cubic yard, and compacts into a firm layer for equipment yards, roads, and driveways. Where specifications permit, recycled crushed concrete base uses this calculation too.

Lane calculations

1. Start with the centerline length and average width for a lane. For pads, multiply length by width.
2. Use a compacted depth of 4 inches for light residential use, 6 for delivery trucks and daily traffic, and 8-12 on soft subgrades or beneath equipment.
3. Divide cubic feet by 27 to get yards; multiply x 1.5 for tons; then leave +10% for compaction.

Lane tonnage and coverage

Building a lane for a second winter

• Remove organic soil before placing the base. Even a thick stone layer over topsoil can have mud work its way upward.
• Where the subgrade is soft or wet, put woven geotextile down before the stone. It adds economical support and keeps a lane more stable.
• Roll each lift before adding another, keeping every lift at 4 inches or less.
• Give the surface a 2-3% crown away from the centerline, directing rain to the sides instead of letting it enter the base.
• For a tidy, low-dust driving surface, place #57 or driveway gravel over the base.
• Hand-spreading 20-plus tons can consume a week. Plan for a skid steer or tractor box blade, since either can handle the work in an afternoon.

Example: a 100-foot farm lane

For one hundred by ten feet at 6 inches, 1,000 x 0.5 = 500 cubic feet = 18.5 cubic yards, or about 28 tons and 30-31 after the allowance. Plan on two tandem loads. For a farm lane, have each load placed at its own spot on the run so material is closer to where it will be spread, rather than piled at the gate.

Equipment, container, and RV pads

Use the same calculation for pads, but select depth based on axle loads. A 12 x 40 RV pad at 6 inches compacted takes about 12 tons. At 8 inches, a 20 x 40 equipment yard requires 27. Because shipping containers focus their load on four corners, install a full 8 inches plus fabric under container pads, even where the ground appears decent, to limit settling by spring.

Using crushed concrete for road base

Recycled concrete base often costs less while compacting and supporting loads similarly to virgin road base. Check county specifications before choosing it, since some require virgin aggregate. It can work well on private lanes and pads. The math remains 1.5 tons per yard, with the same lifts and crown.

Road base by lane and ton

Other calculators