There is no definite size, as anything on this scale and distance is liable to change and distortion.
However, it has generally been estimated that the Virgo Supercluster is at least 110 million light years across.
For comparison our Galaxy is only 100,000 light years across and the Sun is only 8 light minutes from us.
See related link for more information.
The Local group for the clusterThe Virgo Super Clusters for the Supercluster
Earth is in milkyway galaxy which is part of Virgo cluster and Virgo cluster is located in Virgo supercluster. Cluster = A group of galaxies. Supercluster = group of clusters.
The Virgo Supercluster, often just called the Local Supercluster
The Milky Way is part of the Virgo Supercluster.
Every single type.
Our local cluster is known as - well "The Local Cluster", Not very imaginative I know. It is part of the the Virgo Supercluster or Local Supercluster.
Virgo Supercluster
The Virgo Supercluster (in which the Milky Way is located) is about 200 million light years across.
Until now, the Milky Way was believed to be one galaxy in the 2,000 that make up what's known as the Virgo "supercluster".
the Virgo cluster of galaxies is about 60 million light years away from the Sun.
The Earth is 93,000,000 miles from the Sun, on the edge of the Milky Way galaxy, in the Virgo supercluster.
The Solar System contains the Earth-Moon system. The Milky Way galaxy contains the Solar System. The Virgo supercluster contains the Milky Way galaxy. The Universe contains the Virgo supercluster.