Bhagavad Gita, Chapter 10, Verse 42

Or what avails it to you to know all this diversity, O Arjuna? Know this, that I exist, supporting this whole world by a portion of Myself.

The whole of creation is described here as resting inside only a single fraction of this real, larger being.

Krishna closes by waving off the need for more detail, one plain fact is offered as enough to hold onto. Real scale, once stated this directly, doesn't need further listing to make its point.