Math CentralQuandaries & Queries


Question from Carol:

We are having a block foundation installed under our house that measures 80ftX28ft and I need to know how to figure out how much concrete to order. The footer will be 12 inches wide and 4 inches deep all the way around the house. How do I figure the square footage of my house? I know area = LxW but do I double that since there 4 sides to my house?

Hi Carol,

Concrete is usually ordered by the cubic yard. (Contractors often use the term yards to mean cubic yards.) You have four footings, two of them 80 feet long by 12 inches wide by 4 inches deep, and two of them 26 feet long by 12 inches wide by 4 inches deep.


You can use our volume calculator to calculate the volume in cubic yards of each of the four footings and then add the volumes to see how much concrete you need.


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