How Much River Rock for a 8x12 Patio?
How much river rock for a 8x12 patio is a quick volume problem. 96 square feet at 3 inches comes to 0.89 cubic yards. River rock usually weighs about 1.25 to 1.45 tons per cubic yard, so plan on roughly 1.2 tons.
Volume and tonnage calculator →The math for a 8x12 patio
- Area: 8 × 12 = 96 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic feet: 96 × 0.250 = 24.0 cu ft.
- Cubic yards: ÷ 27 = 0.89 yd³.
- Tons: × 1.35 = 1.2 tons.
The volume and tonnage calculator does this for any size.
River rock needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 2 in | 0.59 | 0.8 | 0.9 |
| 3 in | 0.89 | 1.2 | 1.3 |
| 4 in | 1.19 | 1.6 | 1.8 |
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. 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. 1.3 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 about 1.2 tons this job is small enough that bagged material could work; a 0.5 cubic foot bag holds about 1/54 of a yard, so compare the bag count with a bulk minimum.
- Where it drops. Have the truck dump as close to the patio as firm ground allows.
When to choose river rock
Best suited to:
- Dry creek beds and drainage swales
- Decorative borders and planting beds
- Around downspouts to stop splash erosion
Less suited to:
- 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 8x16 area at 3 inches takes about 1.6 tons.
- Weight used here: about 1.35 tons per cubic yard.
Mistakes that throw off the order
- Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
- Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
- 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 river rock for a 8x12 patio?
About 1.2 tons at 3 inches deep, or 1.3 tons with 10 percent extra.
How many cubic yards is a 8x12 patio at 3 inches?
About 0.89 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 8x12?
96 square feet.
Related guides
- How Much Does a Ton of River Rock Cover?
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Does a Ton of Gravel Cover? Depth Chart
- How Much River Rock for a 6x100 Walkway?
- How Much River Rock for a 8x10 Patio?
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