Question 1

How many 80lb bags of concrete do I need for a 10x10 slab at 4 inches thick?

Accepted Answer

A 10x10 foot slab at 4 inches thick requires 1.23 cubic yards (33.3 cubic feet) of concrete. Since one 80lb bag yields 0.60 cubic feet, you need 56 bags of 80lb concrete (or 74 bags of 60lb concrete).

Question 2

What is the yield of 80lb, 60lb, and 40lb bags of Quikrete / Sakrete?

Accepted Answer

One 80lb bag yields 0.60 cu ft (0.022 cu yds). One 60lb bag yields 0.45 cu ft (0.017 cu yds). One 40lb bag yields 0.30 cu ft (0.011 cu yds).

Bags of Concrete Calculator