We are pouring an additional drive way and shop in our back yard. The total square foot of all the concrete is 1200 and the concrete will be 3" deep. We need to know how many cubic yards of concrete to order for the job.



Hi Linda.

Area times depth equals volume, so let's get things in the right units and multiply:

1200 square feet is 1200/(3 x 3) = 400/3 square yards.

3 inches is 3/(12 x 3) = 1/12 yards.

400/3 square yards times 1/12 yards is 400/36 cubic yards.

That's 11 and 1/9 cubic yards you'll need to fill that space.
Stephen La Rocque.