Within each Brahmanda material universe is a secondary material universe managed by Maha-Visnu's expansion, Garbhodakashayi Viṣṇu, who is surrounded by His many servants the demigods lead by Lord Brahma.
Our Brahmanda universe that our secondary universe is in, is considered to be small compared to other Brahmanda universes in the material world.
Yet still, our Brahmanda universe that houses the secondary universe we are in, is a massive 44 quadrillion 444 trillion 444 billion miles in diameter, or twice that size if measured from outer edge of the secondary universe within the Brahmanda universe.
As said above, deep inside the Brahmanda universe at its centre, is found another smaller universe that is just 4 billion miles in diameter according to the 5th Canto of Srimad Bhagavatam.
This unner material secondary universe and its 14 planetary systems, is called "the Bhu-Mandala Earth," not to be confused with the small world we live on also called Earth that exists within one of the 14 planetary systems.
Our small 4 billion mile diameter Bhu-Mandala universe is in the center, housed within the massively huge Brahmanda outer universe.
As said above, the maintainer of the inner Bhu-mandala universe's 14 planetary systems deep inside the Brahmanda universe, is an Maha-Visnu's expansion known as Garbhodakashayi Visnu.
From Him a stem grows from His naval and at the top of the stem is a lotus flower where Lord Brahma resides.
Within the lotus stem exists all 14 planetary systems.
As said above, the Brahmanda universe may even be bigger than the above figures.
The inner Bhu-Mandala secondary universe with its 14 planetary systems, is 4 billion miles in diameter according to the 5th Canto.
However, this figure may have deeper meanings if you add the knowledge of different dimensions existing within that 4 billion miles diameter as well.
This further means the figure of 4 billion miles in diameter is not to be taken literally and needs sensible decoding because it is a fact, our secondary material universe is much larger than 4 billion miles in diameter.
There are seven material layers of the Brahmanda universe that surround the inner Bhu-mandala secondary universe.
The first layer of the outer Brahmanda universe encasing the inner Bhu-Mandala secondary universe, is earth which is 10 times thicker than the 4 billion mile diameter Bhu-Mandala universe which equals-
1 - Bhu-Mandala universe is 4,000,000,000 (4 billion miles in size)
2 - Earth layer is 10×4 = 40,000,000,000 (40 billion miles in diameter)
3 - Water layer is 10×40 = 400,000,000,000 (400 billion miles in diameter)
4 - Fire layer is 10×400 = 4000,000,000,000 (4000 billion which is 4 trillion in diameter)
5 - Air layer is 10×4 = 40,000,000,000,000 (40 trillion in diameter)
6 - Sky layer is 10×40 = 400,000,000,000,000 (400 trillion in diameter)
7 - Ego layer is 10×400 = 4000,000,000,000,000 (4000 trillion which is 4 quadrillion in diameter)
8 - Mahat-tattva layer is 10×4000 = 40,000,000,000,000,000 (40 quadrillion in diameter)
So the full size of our Brahmanda egg shaped material universe (Brahmanda) that houses our secondary universe known as Bhu-Mandala, is a massive 44 quadrillion 444 trillion 444 billion miles in diameter.
Srimad Bhagavatam - "The layers or elements covering the universes are each ten times thicker than the one before, and all the universes clustered together appear like atoms in a huge combination." (SB, Canto 3 Ch 11 text 41)
Srila Prabhupada - "The coverings of the universes are also constituted of the elements of earth, water, fire, air and ether, and each is ten times thicker than the one before. The first covering of the universe is earth, and it is ten times thicker than the universe itself. If the universe is four billion miles in size, then the size of the earthly covering of the universe is four billion times ten.
The covering of water is ten times greater than the earthly covering, the covering of fire is ten times greater than the watery covering, the covering of air is ten times greater than that of the fire, the covering of ether is ten times greater still than that of air, and so on. The universe within the coverings of matter appears to be like an atom in comparison to the coverings, and the number of universes is unknown even to those who can estimate the coverings of the universes." (SB, Canto 3 Ch 11 text 41 Purport)#//#
