How much concrete for a 40 × 60 slab?
A 40 × 60 ft slab (2,400 sq ft) poured 4 inches thick takes 29.63 cubic yards of concrete. With 10% extra for uneven ground and spillage, order 32.59 cubic yards of ready-mix or buy 1467 bags of 80 lb mix.
| Thickness | Exact volume | Order (+10%) | 80 lb bags | 60 lb bags | Typical use |
|---|---|---|---|---|---|
| 4 in | 29.63 yd³ | 32.59 yd³ (24.92 m³) | 1467 | 1956 | Patio, walkway, shed floor |
| 5 in | 37.04 yd³ | 40.74 yd³ (31.15 m³) | 1834 | 2445 | Hot tub pad, light driveway |
| 6 in | 44.44 yd³ | 48.89 yd³ (37.38 m³) | 2200 | 2934 | 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
880 cubic feet = 32.59 cubic yards = 24.92 m³. Above about 1 cubic yard, ready-mix delivery is usually cheaper and faster than bags.
Rough material cost (cheapest option)
$5,541Ready-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 40x60 slab?
At 4 inches thick, 1467 bags of 80 lb concrete mix or 1956 bags of 60 lb mix, including 10% extra. At 6 inches, 2200 bags of 80 lb mix.
Should I use bags or ready-mix for a 40x60 slab?
Ready-mix is usually cheaper and much less work above about 1 cubic yard, and this slab needs 32.59. Under 4–5 yards many suppliers add a short-load fee, so compare a quote with 1467 bags.
How do you calculate concrete for a 40 by 60 slab?
Multiply length × width × thickness in feet: 40 × 60 × (4 ÷ 12) = 800 cubic feet. Divide by 27 to get 29.63 cubic yards, then add 5–10% extra.