Concrete for a 32×50 slab
19.75 cubic yards (978 × 80 lb bags)
for a 32×50 ft slab 4 inches thick: 533.3 cu ft. Bag counts include 10% extra; at 6 inches you need 29.63 yards.
A 32×50 foot slab covers 1600 square feet. At the standard 4 inch thickness for a patio, walkway or shed floor, that is 533.3 cubic feet of concrete, or 19.75 cubic yards. At this size ready-mix is cheaper and far less work than bags: about 21.75 yards, roughly $3,589 before delivery fees, against $6,357 for 978 bags of 80 lb mix.
Concrete for a 32×50 slab by thickness
| Thickness | Cubic yards | Cubic feet | 80 lb bags | 60 lb bags | 40 lb bags |
|---|---|---|---|---|---|
| 3 in | 14.81 | 400 | 734 | 978 | 1467 |
| 4 in | 19.75 | 533.3 | 978 | 1304 | 1956 |
| 5 in | 24.69 | 666.7 | 1223 | 1630 | 2445 |
| 6 in | 29.63 | 800 | 1467 | 1956 | 2934 |
| 8 in | 39.51 | 1,066.7 | 1956 | 2608 | 3912 |
Bag counts include 10% extra for spillage and uneven ground. Cubic yards and cubic feet are the exact volume.
How it’s worked out
- Convert the thickness to feet: 4 in ÷ 12 = 0.333 ft.
- Multiply length × width × thickness: 50 × 32 × 0.333 = 533.33 cu ft.
- Divide by 27 for cubic yards: 533.33 ÷ 27 = 19.753 cu yd.
- Add 10% and divide by the bag yield: 586.67 ÷ 0.6 = 978 bags of 80 lb mix (rounded up).
Under the slab, plan on 4 inches of compacted gravel: about 19.75 cubic yards. For driveways and anything that carries a vehicle, go to 5 or 6 inches and add rebar or wire mesh.
Change the numbers
Other slab sizes
- 30×50 slab
- 28×50 slab
- 36×50 slab
- 26×50 slab
- 32×40 slab
- 25×50 slab
- 24×50 slab
- 40×50 slab
- 32×36 slab
- 22×50 slab
- 32×32 slab
- 20×50 slab
Questions
- How many bags of concrete do I need for a 32×50 slab?
- At 4 inches thick, a 32×50 slab takes 978 bags of 80 lb concrete mix, 1304 bags of 60 lb mix or 1956 bags of 40 lb mix, including 10% extra.
- How many yards of concrete for a 32×50 slab?
- 19.75 cubic yards at 4 inches thick, 24.69 at 5 inches and 29.63 at 6 inches, before adding extra for waste.
- How much does a 32×50 concrete slab cost?
- The concrete alone for a 4 inch 32×50 slab costs about $6,357 in 978 bags of 80 lb mix (at about $7 a bag) or about $3,589 for 21.75 yards of ready-mix (at about $165 a yard, before delivery fees). Professionally poured slabs usually run $6 to $12 per square foot, about $9,600 to $19,200 for 1600 sq ft.
- How much does a 32×50 slab weigh?
- About 38.7 tons at 4 inches thick (concrete weighs about 145 lb per cubic foot).