How Much Pea Gravel for a 12x18 Patio?
A 12 by 18 foot patio is 216 square feet. How much pea gravel for a 12x18 patio depends on depth: at 3 inches it is about 2.00 cubic yards or 2.8 tons. Suppliers usually sell by the ton, so the tonnage is the number to give them.
Volume and tonnage calculator →The math for a 12x18 patio
- Area: 12 × 18 = 216 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic feet: 216 × 0.250 = 54.0 cu ft.
- Cubic yards: ÷ 27 = 2.00 yd³.
- Tons: × 1.4 = 2.8 tons.
The volume and tonnage calculator does this for any size.
Pea gravel needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 2 in | 1.33 | 1.9 | 2.1 |
| 3 in | 2.00 | 2.8 | 3.1 |
| 4 in | 2.67 | 3.7 | 4.1 |
About pea gravel
Because pea gravel is round, it never fully locks. Keep depths modest on walkways and patios so it does not feel like walking on a beach, and use edging. Weight per yard is a planning number; the scale ticket at the yard is the real one.
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. 3.1 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.
When to choose pea gravel
Good uses:
- Patios, walkways and dog runs
- Play areas with proper depth and edging
- Drainage around foundations when sized properly
Less suited to:
- Driveways and steep paths, where it rolls and ruts
- Under pavers as a base
- Areas without edging
Quick reference numbers
- Per inch over 100 sq ft: about 0.43 tons of pea gravel (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.3 tons.
- Another size for comparison: a 12x24 area at 3 inches takes about 3.7 tons.
- Weight used here: about 1.4 tons per cubic yard.
Where estimates go wrong
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
- 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 pea gravel for a 12x18 patio?
About 2.8 tons at 3 inches deep, or 3.1 tons with 10 percent extra.
How many cubic yards is a 12x18 patio at 3 inches?
About 2.00 cubic yards.
How much does a cubic yard of pea gravel weigh?
Usually around 1.3 to 1.5 tons, depending on stone size, fines and moisture.
How deep should pea gravel 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 12x18?
216 square feet.
Related guides
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Pea Gravel for a 12x14 Patio?
- How Much Pea Gravel for a 12x16 Patio?
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