Refreshme Refreshme
Refreshme Refreshme answered Otis Campbell's question

I went to my rural landfill. The things people threw out today would make your head spin. I took home and recycled a few things from the metal scrap pile. ..copper tubing which I'll take in for salvage $$$.  A few other useful things.A lawn mower which just needed a spark plug. It came with … Read more

Refreshme Refreshme
Refreshme Refreshme thanked Tom Jackson's answer

As The Z said, you are looking for volume.

I figured someone somewhere has made some tentative and realistic calculations.  Here is a quote and a link:

Rhuzkan's estimate was that a 30-foot wall would use more than three times the total concrete in the Hoover Dam. With this extra 20 feet of concrete, we’re up toRead more

Refreshme Refreshme
Refreshme Refreshme thanked The Z.'s answer

You have a bit of confusion going on here. AREA is measured in square feet; VOLUME is measured in cubic feet.

We'd need to know the length to multiply times the height to determine the area (sq ft); multiply that sum times the depth (or thickness) to determine the volume (cu ft).