Originally Posted by https://www.cfa.harvard.edu/~dkipping/numberofhabs.html

The Greater Universe

In the last two sections we estimated that there are ~50 million habitable exoplanets and ~25 million habitable exomoons in the Milky Way alone. Let us therefore choose ~100 million habitable environments per galaxy as our order of magnitude estimate i.e. our galaxy is not special. What does this mean for the whole Universe?

The numbers are staggering.

With 100 billion galaxies estimated to exist [15], perhaps many more, we are looking at the total of number of habitable environments exceeding:

10 000 000 000 000 000 000 worlds
= 10 million trillion

10 million trillion, take a moment and just say to that yourself. It is colossal.