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How Much River Rock for a 12x24 Patio?

How much river rock for a 12x24 patio is a quick volume problem. 288 square feet at 3 inches comes to 2.67 cubic yards. River rock usually weighs about 1.25 to 1.45 tons per cubic yard, so plan on roughly 3.6 tons.

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The math for a 12x24 patio

  1. Area: 12 × 24 = 288 sq ft.
  2. Depth in feet: 3 ÷ 12 = 0.250 ft.
  3. Cubic feet: 288 × 0.250 = 72.0 cu ft.
  4. Cubic yards: ÷ 27 = 2.67 yd³.
  5. Tons: × 1.35 = 3.6 tons.

The volume and tonnage calculator does this for any size.

River rock needed by depth

DepthCubic yardsTons (approx.)Tons +10%
2 in1.782.42.6
3 in2.673.64.0
4 in3.564.85.3

About river rock

River rock is smooth, water-worn stone sold in sizes from about 3/4 inch to several inches. Larger sizes cover fewer square feet per ton at the same depth because the voids between stones are bigger. If the yard sells by the cubic yard instead of the ton, use the cubic-yard column directly.

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. Since the patio carries foot traffic and furniture, 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. 4.0 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.

Good and poor uses for river rock

Works well for:

  • Dry creek beds and drainage swales
  • Decorative borders and planting beds
  • Around downspouts to stop splash erosion

Poor fit for:

  • Walking surfaces
  • Driveways
  • Bases under slabs or pavers

Quick reference numbers

  • Per inch over 100 sq ft: about 0.42 tons of river rock (0.31 cubic yards).
  • Per inch over 1,000 sq ft: about 4.2 tons.
  • Another size for comparison: a 14x28 area at 4 inches takes about 6.5 tons.
  • Weight used here: about 1.35 tons per cubic yard.

Common estimating mistakes

  • Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
  • Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
  • 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.

Questions people ask

How many tons of river rock for a 12x24 patio?

About 3.6 tons at 3 inches deep, or 4.0 tons with 10 percent extra.

How many cubic yards is a 12x24 patio at 3 inches?

About 2.67 cubic yards.

How much does a cubic yard of river rock weigh?

Usually around 1.25 to 1.45 tons, depending on stone size, fines and moisture.

How deep should river rock be for a patio?

The table above shows 2 to 4 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.

How many square feet is 12x24?

288 square feet.

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