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How Much Crushed Stone for a 12x20 Patio?

How much crushed stone for a 12x20 patio: at 3 inches deep you need about 2.22 cubic yards, which is roughly 3.1 tons at 1.4 tons per yard. The patio covers 240 square feet, so every inch of depth adds about 0.74 yards.

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The math for a 12x20 patio

  1. Area: 12 × 20 = 240 sq ft.
  2. Depth in feet: 3 ÷ 12 = 0.250 ft.
  3. Cubic feet: 240 × 0.250 = 60.0 cu ft.
  4. Cubic yards: ÷ 27 = 2.22 yd³.
  5. Tons: × 1.4 = 3.1 tons.

The volume and tonnage calculator does this for any size.

Crushed stone needed by depth

DepthCubic yardsTons (approx.)Tons +10%
2 in1.482.12.3
3 in2.223.13.4
4 in2.964.14.6
6 in4.446.26.8

About crushed stone

Crushed stone has fractured faces, so the pieces interlock when compacted. That is why it holds a driveway or pad shape better than round stone of the same size. Ask your supplier for their own tons-per-yard figure, since stone source and moisture shift it.

Preparing the patio

Remove sod, level the area with a slight slope away from the house, and lay landscape fabric if weeds are a concern. Edging keeps loose material inside the patio footprint. This patio sees foot traffic and furniture, 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. 3.4 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 patio as firm ground allows.

Where crushed stone fits

Best suited to:

  • 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 10x20 area at 3 inches takes about 2.6 tons.
  • Weight used here: about 1.4 tons per cubic yard.

Where estimates go wrong

  • Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
  • Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
  • Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
  • 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 crushed stone for a 12x20 patio?

About 3.1 tons at 3 inches deep, or 3.4 tons with 10 percent extra.

How many cubic yards is a 12x20 patio at 3 inches?

About 2.22 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 patio?

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 12x20?

240 square feet.

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