12x12 Concrete Slab: Bags, Yards & Cost
A 12 × 12 ft slab (144 sq ft) 4 in thick is 48.0 cu ft, or 1.78 cu yd: 80 bags of 80 lb Quikrete Concrete Mix (84 with a 5% margin), 107 bags of 60 lb, or 53 bags of 80 lb Sakrete Maximizer. The 80 lb bags weigh 6,400 lb in total.
Your cost and bags vs a truck
Set up for: a 12 × 12 ft slab · Different project?
12x12 slab at 4, 5 and 6 inches
| Thickness | Cu yd | With 5% | 80 lb Quikrete | 60 lb Quikrete | 80 lb Maximizer | 80 lb 5000 Plus |
|---|---|---|---|---|---|---|
| 4 in | 1.78 | 1.87 | 80 | 107 | 53 | 80 |
| 5 in | 2.22 | 2.33 | 100 | 134 | 66 | 100 |
| 6 in | 2.67 | 2.80 | 120 | 160 | 79 | 120 |
Other sizes: 10x10 · 20x20 · 8x8 · 10x12 · 30x30 · 8x10 · 12x24 · 12x36 · 20x30 · 20x40
FAQ
How many bags of concrete for a 12x12 slab?
At 4 in thick: 80 bags of 80 lb Quikrete Concrete Mix or 107 of 60 lb (whole bags, no margin). At 6 in: 120 of 80 lb.
How many yards of concrete for a 12x12 slab?
1.78 cu yd at 4 in, 2.22 at 5 in and 2.67 at 6 in, before the 4–10% NRMCA suggests adding when you order.
How much does a 12x12 concrete slab cost?
We don't publish prices because they change by store and region. Multiply 80 bags by your store's 80 lb bag price, or 1.87 cu yd (4 in, with 5%) by your plant's price per yard plus delivery and short-load fees. Type those into the calculator to compare.
Sources
- Quikrete: QUIKRETE Concrete Mix (No. 1101) data sheet · fetched and reviewed 2026-11-10
- Quikrete: QUIKRETE online project calculator (calculator.js) · fetched and reviewed 2026-11-10
- Sakrete: Sakrete Maximizer Concrete Mix technical data sheet · fetched and reviewed 2026-11-10
- Sakrete: Sakrete 5000 Plus Concrete Mix technical data sheet · fetched and reviewed 2026-11-10
- NRMCA: CIP 31: Ordering Ready Mixed Concrete · fetched and reviewed 2026-11-10