3.5 to 4 yards, depending to some extent on where you live and building codes. 6" uniform thickness would require around 3.5 yards.
25 Yards of concrete
37.03 yards
A 40x60x6in slab requires 44.44 cubic yards of cement.
about 5 yards if your slab is 4" deep
A 40'x40'x6" slab requires 29.63 cubic yards of cement.
3.95 cubic yards of cement are needed for a slab that size.
1.19 Cubic Yards
25 Yards of concrete
8 square yards
You will need 27.6 cubic yards of cement.
11.852 cubic yards
You need to specify the slab's width and the length as well.
how many yards of concrete will i need to do a 20 x20 x4 slab
37.03 yards
For a 4-inch depth you will need 7.41 cubic yards.
You need to specify the slab's width and the length as well.
1.5 cubic yards of cement are needed for an 11' x 11' x 4" slab.