None.
There are no yards in a cubic yard, because a yard is a linear unit of distance, whereas a cubic yard is a spacial unit of volume.
A cubic yard is the volume occupied by a cube that measures...
You need to know the depth of area to be filled first. A cubic yard is a cube measuring 1 yard on each side. So for instance if you are filling a hole that is 2 yards by 2 yards big and 1 yard deep...