How much concrete do I need for a 12×20 patio?
≈ 2.96 cubic yards
That’s about 134 bags of 80-lb concrete mix (or 178 60-lb bags) for a 12×20 area at 4″ thick.
A 12 ft × 20 ft patio is 240 square feet. Poured at the standard 4-inch slab thickness, that’s 80.0 cubic feet of concrete — about 2.96 cubic yards.
| Area | 240 sq ft |
| Thickness | 4 in |
| Volume | 2.96 cu yd (80.0 cu ft) |
| 80-lb bags | 134 bags |
| 60-lb bags | 178 bags |
Tip: buy ~10% extra for spillage and uneven subgrade. For a thicker pour (driveways are often 5–6″), use the calculator to adjust.
Change the size → open the concrete calculatorGrab the supplies
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