Cubic feet
—
Project guide
Concrete for a Patio?
How much concrete for a patio slab — standard thickness, whether you need reinforcement, and a calculator for your exact size.
Dimensions
FIG. 01Volume ÷ 27 = cubic yards. Pros order to the nearest ½ yard and add a waste margin — running short mid-pour risks a cold joint.
You need
—cu yd
Order to nearest ½ yd → — · —
Cubic meters
—
80 lb bags
—
60 lb bags
—
Est. weight
—
Best buy
see above
Sizing it right
A patio is the classic 4-inch slab — simple to estimate, and often a candidate for bags if it's small.
4 inches, lightly reinforced
4 inches is standard for a patio. It's not carrying vehicles, so heavy rebar isn't required — welded-wire mesh or fiber is typical to control cracking. A compacted base under it still matters for a slab that won't heave.
Bags or truck?
A small 10×10 patio is about 1.2 cubic yards — borderline. A 16×20 is nearly 4 yards — clearly a truck. The calculator below shows bag and truck counts; the breakeven tool settles close calls.
Shape it right
Round or curved patio? Use the round slab calculator. For an L-shape, split it into rectangles and add the results.
Worked example
A 12 × 16 ft patio at 4 inches: 12 × 16 × 0.333 ft = 64 ft³, plus 10% waste ≈ 70.4 ft³, ÷ 27 =
2.61 cubic yards, or about 118 × 80 lb bags. At nearly 3 yards this is right at the edge of ready-mix territory — run it through the bags-vs-ready-mix tool to see which is cheaper for your local prices.
Concrete by patio size (4 in thick, 10% waste)
| Patio size | Cubic yards | 80 lb bags |
|---|---|---|
| 8 × 10 ft | 1.09 | 49 |
| 10 × 10 ft | 1.36 | 62 |
| 12 × 12 ft | 1.96 | 89 |
| 12 × 16 ft | 2.61 | 118 |
| 16 × 16 ft | 3.48 | 157 |
| 16 × 20 ft | 4.35 | 196 |
FAQ
How thick should a concrete patio be?
4 inches over a compacted base is standard. Patios don't carry vehicle loads, so mesh or fiber for crack control is usually enough rather than heavy rebar.
How much concrete for a 12x12 patio?
About 1.8 cubic yards at 4 inches. Enter your exact dimensions above for the precise volume, bag count, and whether bags or a truck is cheaper.