Concrete for a 16x16 Slab
Order 3.48 yd with 10% waste — or 143 × 80 lb bags / 190 × 60 lb bags.
By thickness
| Thickness | Cubic yards | +10% waste | 80 lb bags | Typical use |
|---|---|---|---|---|
| 4" | 3.16 | 3.48 | 143 | Patio, shed pad, walkway |
| 5" | 3.95 | 4.35 | 178 | Light vehicle traffic |
| 6" | 4.74 | 5.21 | 214 | Driveway, garage |
Bags or the truck?
For this 256 sq ft slab at 4": bags ≈ $930 (143 × 80 lb — that's 11,440 lb of mixing) vs ready-mix ≈ $565 delivered. The truck wins here. Prices are national ballparks — your local quote rules.
Adjust the numbers
Common questions
How much concrete do I need for a 16x16 slab?
A 16x16 slab at the standard 4-inch thickness needs 3.16 cubic yards of concrete — order 3.48 yards with a 10% waste margin. At 6 inches it needs 4.74 yards.
How many bags of concrete for a 16x16 slab?
At 4 inches thick: 143 bags of 80 lb concrete mix or 190 bags of 60 lb. At this volume, delivered ready-mix is usually cheaper and far less work than mixing bags.
Should I use bags or ready-mix for a 16x16 slab?
Ready-mix. Bags for this slab would cost about $930 in material and require mixing 11,440 lb by hand; a delivered order runs roughly $565 and arrives ready to pour.