How much concrete for a 12 × 16 slab?
A 12x16 slab is 192 sq ft. At the standard 4-inch depth it takes 2.61 cubic yards of concrete (118 80 lb bags) including the recommended 10% waste factor.
| Thickness | Cubic yards (incl. 10% waste) | 80 lb bags | 60 lb bags |
|---|---|---|---|
| 4 in (patio, shed base) | 2.61 yd³ | 118 | 157 |
| 5 in (light vehicles) | 3.26 yd³ | 147 | 196 |
| 6 in (driveway, garage) | 3.91 yd³ | 176 | 235 |
Estimates are for planning. Confirm quantities against your measured site and product packaging before ordering, and follow local building codes.
Bags or ready-mix for a 12x16 slab?
At 2.61 cubic yards for the 4-inch pour, ready-mix delivery is the realistic choice: that volume means hand-mixing 118 bags, which is a full day of brutal work and risks cold joints between batches. Expect roughly $392 – $574 for the concrete delivered at 2026 prices ($150 to $220 per cubic yard), and ask about the short-load fee, which can add $50 to $150 on small pours. The formula behind these numbers is on the concrete calculator: length × width × depth, converted to cubic yards, plus your chosen waste factor.
Before ordering, prepare a compacted gravel base of 4 inches (see the gravel calculator for quantities) and read what a finished slab really costs for forms, labor, and finishing on top of the material price.
Frequently asked questions
How many bags of concrete do I need for a 12x16 slab?
At 4 inches thick, a 12x16 slab needs about 118 80 lb bags or 157 60 lb bags, including 10% waste. At 192 sq ft, ready-mix delivery is usually more practical than mixing bags.
How much does concrete for a 12x16 slab cost?
The concrete alone for a 12x16 slab at 4 inches (2.61 cubic yards) runs roughly $392 – $574 delivered at typical 2026 ready-mix prices of $150 to $220 per cubic yard, before any short-load fee. A finished slab with labor, forms, and base costs several times the material.
Should a 12x16 slab be 4 or 6 inches thick?
Four inches suits patios, walkways, and shed bases. Go to 5 or 6 inches if the slab will carry vehicles or heavy point loads. The jump from 4 to 6 inches adds about 50% more concrete.