How Much Concrete for a 10 × 12 Slab?
A 10 × 12 ft slab is 120 sq ft. It needs 1.63 cubic yards of concrete at 4 inches thick or 2.44 yd³ at 6 inches, including 10% extra.
| Order | 4 in thick | 6 in thick |
|---|---|---|
| Cubic yards | 1.63 | 2.44 |
| 80-lb bags | 74 | 110 |
| 60-lb bags | 98 | 147 |
| 50-lb bags | 118 | 176 |
| 40-lb bags | 147 | 220 |
| Cubic meters | 1.25 | 1.87 |
Concrete needed
1.63 cubic yards
44.0 ft³ · 1.25 m³ · includes 10% extra
You need about 1.63 cubic yards of concrete, or 74 bags of 80 lb mix.
Bags of premix
- 14740 lb bags
- 11850 lb bags
- 9860 lb bags
- 7480 lb bags
- —20 kg bags
- —25 kg bags
- Before extra1.48 yd³ (40.0 ft³)
- Weight of bags5,920 lb
- Per hole—
- Ready-mix costAdd a price per yd³
- Bagged costAdd a price per bag
One 80 lb bag makes about 0.60 ft³ (manufacturer's published yield). Bags are rounded up.
At 1.63 yd³ that is 74 × 80 lb bags (5,920 lb) to mix. Most people order ready-mix at this size; ask suppliers for their minimum load and any short-load fee.
Estimate only, not a quote or engineering advice. Disclaimer
A 10 × 12 ft slab fits a common 10 × 12 storage shed or a small patio for a table and chairs.
10 × 12 slab at other thicknesses
| Thickness | yd³ exact | yd³ +10% | 80-lb bags | 60-lb bags |
|---|---|---|---|---|
| 3.5 in | 1.30 | 1.43 | 65 | 86 |
| 4 in | 1.48 | 1.63 | 74 | 98 |
| 5 in | 1.85 | 2.04 | 92 | 123 |
| 6 in | 2.22 | 2.44 | 110 | 147 |
| 8 in | 2.96 | 3.26 | 147 | 196 |
How it's worked out
For bags, the 44.0 ft³ (with extra) is divided by each bag's yield: 0.60 ft³ for 80 lb, 0.45 for 60 lb, 0.375 for 50 lb and 0.30 for 40 lb, then rounded up. At 4 inches the slab itself weighs about 5,600 lb, using the 140 lb/ft³ unit weight QUIKRETE lists for its Concrete Mix.
Bags or a truck?
At 1.63 yd³ you would need 74 × 80-lb bags (about 5,920 lb) and a long session with a mixer and helpers. Most people order ready-mix at this size: call suppliers with the yardage and ask for their minimum load and any short-load fee.
Don't forget the base: most slabs sit on a compacted layer of gravel, and thicker edges or footings around the perimeter add concrete. Use the footing calculator for a thickened edge.
Frequently asked questions
How many yards of concrete for a 10x12 slab?
1.48 cubic yards at 4 inches thick and 2.22 yd³ at 6 inches, before waste. With 10% extra, order 1.63 or 2.44 yd³.
How many bags of concrete for a 10x12 slab?
At 4 inches with 10% extra: 74 bags of 80-lb mix, 98 of 60 lb, 118 of 50 lb or 147 of 40 lb. At 6 inches: 110 bags of 80 lb or 147 of 60 lb.
How many cubic feet of concrete for a 10x12 slab?
40.0 ft³ at 4 inches (120 sq ft × 4 ÷ 12) and 60.0 ft³ at 6 inches, before waste.
How thick should a 10x12 slab be?
Four inches is usual for patios, walkways and shed pads. Garage floors, driveways and pads for heavy loads are commonly 5 to 6 inches. Follow local code or your plans for anything structural.
Other slab sizes
Related
Sources
- QUIKRETE: Concrete Mix No. 1101 data sheet (Revised Oct 2022; checked Nov 11, 2026)