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How Much Crushed Stone for a 20x30 Parking Pad?

How much crushed stone for a 20x30 parking pad: at 4 inches deep you need about 7.41 cubic yards, which is roughly 10.4 tons at 1.4 tons per yard. The parking pad covers 600 square feet, so every inch of depth adds about 1.85 yards.

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The math for a 20x30 parking pad

  1. Area: 20 × 30 = 600 sq ft.
  2. Depth in feet: 4 ÷ 12 = 0.333 ft.
  3. Cubic feet: 600 × 0.333 = 200.0 cu ft.
  4. Cubic yards: ÷ 27 = 7.41 yd³.
  5. Tons: × 1.4 = 10.4 tons.

The volume and tonnage calculator does this for any size.

Crushed stone needed by depth

DepthCubic yardsTons (approx.)Tons +10%
2 in3.705.25.7
3 in5.567.88.6
4 in7.4110.411.4
6 in11.1115.617.1

About crushed stone

Most quarries sell crushed stone by a size number or a screen size. Clean crushed stone drains well; stone with fines packs harder but sheds water more slowly. If the yard sells by the cubic yard instead of the ton, use the cubic-yard column directly.

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. Since the parking pad carries parked vehicles, a little extra depth is cheap insurance.

Ordering tips

  • Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
  • Delivery size. 11.4 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.

Good and poor uses for crushed stone

Works well for:

  • Driveway top courses and parking pads
  • Shed and hot tub bases
  • Backfill behind walls when a clean size is used

Think twice for:

  • Barefoot areas, since angular stone is rough
  • Play areas
  • Places that need a smooth rolling surface for wheels

Quick reference numbers

  • Per inch over 100 sq ft: about 0.43 tons of crushed stone (0.31 cubic yards).
  • Per inch over 1,000 sq ft: about 4.3 tons.
  • Another size for comparison: a 15x30 area at 4 inches takes about 7.8 tons.
  • Weight used here: about 1.4 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.
  • Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
  • Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
  • Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.

Questions people ask

How many tons of crushed stone for a 20x30 parking pad?

About 10.4 tons at 4 inches deep, or 11.4 tons with 10 percent extra.

How many cubic yards is a 20x30 parking pad at 4 inches?

About 7.41 cubic yards.

How much does a cubic yard of crushed stone weigh?

Usually around 1.35 to 1.5 tons, depending on stone size, fines and moisture.

How deep should crushed stone be for a parking pad?

The table above shows 2 to 6 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.

How many square feet is 20x30?

600 square feet.

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