As a guideline, 4 inches thick, but it would depend on what is going to be sitting on top of it. You may need thicker and/or to reinforce it with rebar.
one yard of cement will make a 8 x 10 square foot slab at 4 inches thick, that's 80 sq. feet per yard of cement at 4 inches thick.
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9' by 18' by 4" thick requires at least two cubic yards.
4 To 6 inches
A 40x60x6in slab requires 44.44 cubic yards of cement.
This can't be answered because you have not given the third dimension. You must say how thick the slab is.
A 16' x 8' by 4" slab requires 3.56 cubic yards of cement.
one yard of cement will make a 8 x 10 square foot slab at 4 inches thick, that's 80 sq. feet per yard of cement at 4 inches thick.
9.3 cubic yards of cement is required for this slab.
6.67 Cubic Yards
A minimum of 5.93 cubic yards is needed.
A minimum of 1.23 cubic yards at 4" thick.
0.86 cubic yards is needed.
You'll need 1 cubic yard.
You will need at least 9.68 cubic yards of cement.
It depends on the thickness of slab. A yard of cement contains 9 cubic feet. Thus, it would cover 9 square feet if the slab was 1 foot thick. For a 4 inch thick slab, it would cover 3 times as much area, or 27 square feet.
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