Srimad Bhagavatam Canto 03, Chapter 11, Text 40

SB 3.11.40

vikaraih sahito yuktair
 visesadibhir avrtah
andakoso bahir ayam
 pañcasat-koti-vistrtah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
This phenomenal material world is expanded to a diameter of four billion miles, as a combination of eight material elements transformed into sixteen further categories, within and without, as follows.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
As explained before, the entire material world is a display of sixteen diversities and eight material elements. The analytical studies of the material world are the subject matter of Sankhya philosophy. The first sixteen diversities are the eleven senses and five sense objects, and the eight elements are the gross and subtle matter, namely earth, water, fire, air, sky, mind, intelligence and ego. All these combined together are distributed throughout the entire universe, which extends diametrically to four billion miles. Besides this universe of our experience, there are innumerable other universes. Some of them are bigger than the present one, and all of them are clustered together under similar material elements as described below.
Srimad Bhagavatam Canto 03, Chapter 11, Text 39
Srimad Bhagavatam Canto 03, Chapter 11, Text 41