Astronomers estimate that there are hundreds of billions to trillions of galaxies in the observable universe, with a commonly cited range of about 200 billion to 2 trillion galaxies , and some recent work suggesting the true number could be even higher.

Quick Scoop: The Big Number

  • Traditional estimates: around 100–200 billion galaxies in the observable universe.
  • Updated Hubble- and model-based estimates: up to about 2 trillion galaxies.
  • Newer theoretical and observational arguments: possibly 6–20 trillion faint, tiny galaxies that we currently struggle to detect.

So when people ask “how many galaxies are there in the universe?” , the honest, modern answer is:

At least hundreds of billions, probably into the trillions, and we still haven’t seen them all.

Observable vs “Entire” Universe

When you see these huge numbers, they nearly always refer to the observable universe , not the whole universe.

  • The observable universe is a sphere centered on us, about 92 billion light-years across , limited by how far light has had time to travel since the Big Bang.
  • Beyond that horizon, space almost certainly continues, potentially with many more galaxies we will never be able to see because their light can’t reach us.

So strictly speaking, the question “how many galaxies are there in the universe” doesn’t have a firm answer—only the observable part can be estimated.

How Scientists Get These Estimates

Astronomers don’t count galaxies one by one across the sky; they:

  1. Take ultra-deep images
    • Telescopes like Hubble and JWST stare at tiny patches of sky (sometimes an area like a pinhead at arm’s length) to reveal extremely faint and distant galaxies.
 * In one such deep field, around **5,500 galaxies** were found in a very small region.
  1. Extrapolate to the whole sky
    • They assume that tiny patch is “typical” and scale up to the full sky, giving early estimates of around 170 billion galaxies , later revised higher.
  1. Add galaxies too faint to see
    • Theoretical models and simulations suggest there are many small, dim galaxies that current telescopes miss.
 * Including these “hidden” galaxies pushes estimates to **2 trillion** and possibly in the **6–20 trillion** range.

Why the Estimates Changed Over Time

  • Older estimates (100–200 billion) came from earlier sky surveys and less sensitive telescopes.
  • Hubble Ultra Deep Field and similar observations revealed many more faint galaxies, leading to the 2 trillion figure.
  • Recent analyses and simulations argue that even Hubble misses most tiny, faint galaxies, pushing the possible number to between 6 and 20 trillion.
  • New telescopes like JWST are finding additional very early, distant galaxies, tightening—but also complicating—these estimates.

A nice way to think of it: every time we build a better telescope and look deeper, the universe gets more crowded.

Different Numbers You’ll See (At a Glance)

Below is a simple view of the main estimates you might encounter:

[9][7][3] [6][10][3] [5]
Source / Method Estimated number of galaxies What it really means
Classic textbook value 100–200 billion Lower-limit count based on older deep-field surveys of the observable universe.
Hubble + improved models ≈2 trillion Includes many faint galaxies inferred from 3D modeling of Hubble images.
Recent theoretical + observational work ≈6–20 trillion Accounts for very small, ultra-faint galaxies likely far beyond current detection limits.

Forum & “Trending Topic” Angle

On science forums and Q&A communities, you’ll often see answers like:

“Somewhere between 200 billion and 2 trillion in the observable universe”

This reflects the conservative range that’s well supported by observational data. More speculative discussions sometimes reference the 6–20 trillion range, which is rooted in current simulations and extrapolations but still under active debate.

As new JWST results roll in through the mid‑2020s, this remains a trending topic in astronomy news and public science outlets, because each new deep survey has the potential to revise those numbers again.

TL;DR:
In the observable universe , there are at least about 200 billion galaxies , likely around 2 trillion , and possibly 6–20 trillion when you include galaxies too small and faint for today’s telescopes—while the total in the entire universe is almost certainly even larger and currently unknowable.

Information gathered from public forums or data available on the internet and portrayed here.