Math CentralQuandaries & Queries


Question from Daniel:

I need to calculate the weight of Concrete in a slab that measures 2' x 4' x 4" thick.
I am pricing out a job and have two different size stones to work with, the second stone measures
2' x 2' x 4".

Hi Daniel,

You can find the volume in cubic yards of the individual pieces using our volume calculator. For the weight you need to know the density of the concrete in pounds per cubic yard. I found some reference to the density and it seems to vary considerably, depending on the aggregate used in the concrete. You can find some information at

The density here is given in kilograms per cubic meter but you can have Google do the conversion. For example if your concrete is 2400 kg/m3 then type 2400 kilograms/cubic meter in pounds/cubic yard into the Google search window and you will receive the response (2 400 kilograms) / (cubic meter) = 4 045.33185 pounds / (cubic yard). Multiply the volume in cubic yards by 4045.33 to obtain the weight in pounds.

I hope this helps,

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