converting cylinder to cubic ft and then to cubic yards

[Unregistered]

need to find how much concrete to mix for anchor holes
the hole diameter is 24" the depth is 5'
so 24/12=2
so to figure cubic ft would be 3.14*2*5=31.4
then to cubic yards 31.4/3=10.466
is this correct?

[JohnS]

Re: converting cylinder to cubic ft and then to cubic yards

need to find how much concrete to mix for anchor holes
the hole diameter is 24" the depth is 5'
so 24/12=2
so to figure cubic ft would be 3.14*2*5=31.4
then to cubic yards 31.4/3=10.466
is this correct?

No the diameter is 2' as you noted, but the volume is
V = (pi/4)*D²*H = 0.785*4*5 = 15.71 ft³

1 yd = 3 ft, but
1 yd³ = 3³ ft³ = 27 ft³, so 0.6 yd³