How much concrete for a 8 × 10 slab?
A 8 × 10 ft slab (80 sq ft) poured 4 inches thick takes 0.99 cubic yards of concrete. With 10% extra for uneven ground and spillage, order 1.09 cubic yards of ready-mix or buy 49 bags of 80 lb mix.
| Thickness | Exact volume | Order (+10%) | 80 lb bags | 60 lb bags | Typical use |
|---|---|---|---|---|---|
| 4 in | 0.99 yd³ | 1.09 yd³ (0.83 m³) | 49 | 66 | Patio, walkway, shed floor |
| 5 in | 1.23 yd³ | 1.36 yd³ (1.04 m³) | 62 | 82 | Hot tub pad, light driveway |
| 6 in | 1.48 yd³ | 1.63 yd³ (1.25 m³) | 74 | 98 | Driveway, garage floor |
Bag counts include the 10% extra and assume 0.60 ft³ per 80 lb bag and 0.45 ft³ per 60 lb bag.
Change the size, thickness or price
29.3 cubic feet = 1.09 cubic yards = 0.83 m³. Above about 1 cubic yard, ready-mix delivery is usually cheaper and faster than bags.
Rough material cost (cheapest option)
$185Ready-mix often has a short-load fee under 4–5 yd³. Rough 2026 US prices, edit to match local quotes.
FAQ
How many bags of concrete for a 8x10 slab?
At 4 inches thick, 49 bags of 80 lb concrete mix or 66 bags of 60 lb mix, including 10% extra. At 6 inches, 74 bags of 80 lb mix.
Should I use bags or ready-mix for a 8x10 slab?
Ready-mix is usually cheaper and much less work above about 1 cubic yard, and this slab needs 1.09. Under 4–5 yards many suppliers add a short-load fee, so compare a quote with 49 bags.
How do you calculate concrete for a 8 by 10 slab?
Multiply length × width × thickness in feet: 8 × 10 × (4 ÷ 12) = 26.7 cubic feet. Divide by 27 to get 0.99 cubic yards, then add 5–10% extra.