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Bag & Bucket

Concrete for a 12x24 Slab: Yards & Bags

A 12 × 24 ft slab at 4 inches thick is 3.56 cubic yards. With 10% extra for waste, plan on 3.91 cubic yards: 176 bags of 80 lb or 235 bags of 60 lb mix. Change the thickness below.

3.91 cubic yards of concrete

Cubic yards
3.91
Cubic feet
105.6
80 lb bags
176
60 lb bags
235
40 lb bags
352
  • Includes 10% extra for spillage and uneven ground.
  • Bag yields: 80 lb ≈ 0.60 cu ft, 60 lb ≈ 0.45 cu ft, 40 lb ≈ 0.30 cu ft.
  • Over about 1 cubic yard, ready-mix delivery is usually cheaper and easier than mixing bags by hand.

Use the full concrete calculator for any size →

Frequently asked questions

How many bags of concrete for a 12x24 slab?

About 176 bags of 80 lb concrete at 4 inches thick, including 10% extra.

Developers: GET /api/concrete-calculator returns JSON.