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Concrete Calculator

Enter slab dimensions and bag size to calculate concrete volume and the number of bags needed.

33.3 ft³
Concrete volume
1.23 yd³
For ready-mix delivery
56 bags
80 lb bags needed

How to use this tool

  1. 1Enter slab length, width, and thickness.
  2. 2Choose a bag size.
  3. 3See volume and bags needed.

Frequently asked questions

When should I use ready-mix instead of bags?+

For larger pours (typically over 1 cubic yard), ready-mix delivery is usually more practical and cost-effective than bagged concrete.