How Much Concrete for a 8x10 Slab?
A 8×10 ft slab covers 80 sq ft. At the standard 4-inch thickness it needs 0.99 cubic yards of concrete – about 49 bags of 80 lb mix including 10% extra. Adjust the thickness below for your project.
Concrete for a 8x10 slab by thickness
| Thickness | Cubic yards | Yards +10% | 80 lb bags | 60 lb bags | Ready-mix cost* |
|---|---|---|---|---|---|
| 4 in | 0.99 | 1.09 | 49 | 66 | $179 |
| 5 in | 1.23 | 1.36 | 62 | 82 | $224 |
| 6 in | 1.48 | 1.63 | 74 | 98 | $269 |
*At about $165 per cubic yard before delivery and short-load fees. Bag counts include 10% extra.
How it is calculated
8 ft × 10 ft × (4 in ÷ 12) = 26.7 cu ft
26.7 cu ft ÷ 27 = 0.99 cubic yards
80 lb bags = 26.7 × 1.10 ÷ 0.60 = 49
Which thickness do you need?
- 4 inches – patios, walkways, shed floors and most residential garage floors.
- 5–6 inches – driveways, hot tub pads, and garages for heavier trucks or RVs.
- Add 4–6 inches of compacted gravel base underneath and use rebar or wire mesh for slabs larger than about 10×10 ft.
Frequently asked questions
How many yards of concrete for a 8x10 slab?
A 8x10 slab (80 sq ft) needs 0.99 cubic yards at 4 inches thick, 1.23 yd³ at 5 inches and 1.48 yd³ at 6 inches, before waste.
How many bags of concrete for a 8x10 slab?
At 4 inches thick with 10% extra, you need about 49 bags of 80 lb concrete mix or 66 bags of 60 lb mix.
Should I use bags or ready-mix for a 8x10 slab?
At 1.1 cubic yards, ready-mix delivery is usually faster and more consistent than mixing 49 bags by hand. Many suppliers charge a short-load fee under 3–4 yards.