How Much Concrete for a 24x24 Slab?

7.82 cu yd

A 24 × 24 ft slab poured 4 inches thick needs about 7.82 cu yd of concrete, including 10% extra for spillage and uneven ground. That is 211.2 cu ft, or 353 bags of 80 lb premix concrete. Best option: order ready-mix (truck).

Concrete for a 24 × 24 ft slab by thickness (10% extra included)

ThicknessCubic yardsCubic feet80 lb bags
3 in5.87 cu yd158.4 cu ft264 bags
4 in7.82 cu yd211.2 cu ft353 bags
5 in9.78 cu yd264 cu ft440 bags
6 in11.73 cu yd316.8 cu ft528 bags

Adjust the numbers

The calculator below is pre-filled with the numbers above. Change any value to match your project.

Slab / Patio
ft
ft
in
4 in is standard for patios and walkways; 6 in for driveways.
Options
%
Add 5–10% for spillage and uneven ground.
Concrete needed7.82 cu yd
In cubic meters
5.98 m³
In cubic feet
211.2 cu ft
80 lb bags
353 bags
Best option
Order ready-mix (truck)

How it is calculated

Concrete is sold by volume, so the calculator multiplies length × width × thickness after converting every measurement to feet. Thickness and depth are usually measured in inches, so they are divided by 12 first.

For round columns and post holes the volume is π × radius² × depth.

Open the full concrete calculator for other shapes, a worked example and FAQs.

Other common sizes