Question

What is the actual size of the universe?

Answer 1

In my opinion, "`the` universe' is undefined. `Our` universe is 'observable universe'. Consensus is awaited.

Explanation:

There are approximations for 2 or 3 significant digits to the size of our galaxy Milky Way (MW). MW might be like an `elongated` oblate spheroid, with axes nearly 6.5 E+04 light years across and some thousands of light years bulge, at its Black Hole center. MW comprises billions of stars. There are similar (larger/smaller) galaxies around MW that are studied, using ever-updating technology. As of now, an affirmative answer on your question is yet to come. Also, consensus on multi-universe and parallel-universe theories are awaited..