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How Much Road Base for a 24x20 Parking Pad?

How much road base for a 24x20 parking pad: at 4 inches deep you need about 5.93 cubic yards, which is roughly 8.9 tons at 1.5 tons per yard. The parking pad covers 480 square feet, so every inch of depth adds about 1.48 yards.

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The math for a 24x20 parking pad

  1. Area: 24 × 20 = 480 sq ft.
  2. Depth in feet: 4 ÷ 12 = 0.333 ft.
  3. Cubic feet: 480 × 0.333 = 160.0 cu ft.
  4. Cubic yards: ÷ 27 = 5.93 yd³.
  5. Tons: × 1.5 = 8.9 tons.

The volume and tonnage calculator does this for any size.

Road base needed by depth

DepthCubic yardsTons (approx.)Tons +10%
4 in5.938.99.8
6 in8.8913.314.7
8 in11.8517.819.6

About road base

Road base (also called base rock, ABC, or Class 2 base in different states) is a graded mix of stone and fines made to compact into a load-bearing layer. Weight per yard is a planning number; the scale ticket at the yard is the real one.

Preparing the parking pad

Dig out organic soil, compact the subgrade and set an edge so the stone does not migrate onto the lawn. A pad that holds parked weight for long periods benefits from a dense base under the surface stone. This parking pad sees parked vehicles, so match the depth to that load rather than to the minimum.

Ordering tips

  • Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
  • Delivery size. 9.8 tons fits in a single typical dump truck load; small loads may carry a delivery fee. See how many tons of gravel in a dump truck.
  • Bulk vs bags. At this size bulk delivery is usually the practical choice.
  • Where it drops. Have the truck dump as close to the parking pad as firm ground allows.

When to choose road base

Good uses:

  • Base under asphalt and concrete
  • Gravel roads and drives
  • Equipment and shed pads

Less suited to:

  • Drainage layers
  • Decorative surfaces
  • Surfaces that will stay uncompacted

Quick reference numbers

  • Per inch over 100 sq ft: about 0.46 tons of road base (0.31 cubic yards).
  • Per inch over 1,000 sq ft: about 4.6 tons.
  • Another size for comparison: a 12x24 area at 4 inches takes about 5.3 tons.
  • Weight used here: about 1.5 tons per cubic yard.

Mistakes that throw off the order

  • Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
  • Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
  • Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
  • Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.

Questions people ask

How many tons of road base for a 24x20 parking pad?

About 8.9 tons at 4 inches deep, or 9.8 tons with 10 percent extra.

How many cubic yards is a 24x20 parking pad at 4 inches?

About 5.93 cubic yards.

How much does a cubic yard of road base weigh?

Usually around 1.4 to 1.65 compacted tons, depending on stone size, fines and moisture.

How deep should road base be for a parking pad?

The table above shows 4 to 8 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.

How many square feet is 24x20?

480 square feet.

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