---
title: "Massive numbers: putting the mass of the observable universe into perspective"
url: "https://lui.vn/massive-numbers-putting-the-mass-of-the-observable-universe-into-perspective/"
language: "en"
type: "article"
published: "2023-04-05T15:01:15+00:00"
modified: "2026-07-03T10:23:48+00:00"
categories: ["Curiosity & Science"]
kicker: "Mass Of Everything"
intro: "The mass of the observable universe: 2x10^53 kg. A number with 54 decimal places. Putting cosmic scale into perspective - or trying to."
image: "https://lui.vn/wp-content/uploads/2023/04/hubble-displays-a-dwarf-spiral-galaxy-1920x1080.jpg"
image_credits: "Image: Hubble Displays a Dwarf Spiral Galaxy by NASA/Hubble"
---

# Massive numbers: putting the mass of the observable universe into perspective

The mass of ordinary matter in the [observable universe](https://en.wikipedia.org/wiki/Universe) is estimated to be ≈2×10^53 kg or ≈200 sexdecillion kilograms, a number with 54 decimal places. Or ≈2×10^50 t aka ≈200 quindecillion metric tons. Ordinary matter means without theoretical [dark matter](https://en.wikipedia.org/wiki/Dark_matter), which is estimated to make up ≈84.5% of the total matter in the universe. Yet, it is hypothetical and will therefore be ignored in this article.

What does this number mean? Well, the first [Death Star from Star Wars](https://web.archive.org/web/20201022043239/https://medium.com/the-cosmic-companion/how-much-would-it-cost-to-build-a-death-star-db82b5f35868) is estimated to have a mass of ≈1,200,000,000,000,000,000 t or ≈1.2 quadrillion metric tons. The mass of ordinary matter in the observable universe divided by the mass of the Death Star yields ≈166,667,000,000,000,000,000,000,000,000 Death Stars or ≈166 decillion 667 nonillion Death Stars. That’s more than the number of stars in the universe, which is estimated to be ≈1×10^24 or ≈1 septillion.

For comparison, the mass of the Sun is approximately ≈1.988435×10^27 t or ≈1 octillion 988 septillion 435 sextillion metric tons or [1 solar mass M☉](https://en.wikipedia.org/wiki/Solar_mass), a standard unit of mass in astronomy . Thus, the estimated mass of ordinary matter in the observable universe is ≈2×10^50 t / M☉, which is equal to ≈100,581,613,178,202,958,608,151 suns, or ≈100 sextillion 581 quintillion 613 quadrillion 178 trillion 202 billion 958 million 608 thousand 151 suns.

Bigger? Yes, bigger! The estimated [mass of our Milky Way](https://en.wikipedia.org/wiki/Milky_Way#Mass) is about ≈3×10^39 t or ≈3 duodecillion metric tons. Thus, the mass of ordinary matter in the observable universe is equal to the mass of ≈66 billion 666 million Milky Ways.

As of March 2023, [Phoenix A](https://en.wikipedia.org/wiki/Phoenix_Cluster#Supermassive_black_hole) is the most massive black hole in the category of supermassive black holes known to date. Its estimated mass is ≈1×10^11 M☉ or ≈100 billion solar masses. This means that the mass of ordinary matter in the observable universe divided by the mass of Phoenix A is ≈800 billion.

Even bigger? Sure is! The [Hercules-Corona Borealis Great Wall](https://en.wikipedia.org/wiki/Hercules%E2%80%93Corona_Borealis_Great_Wall) is the largest known structure in the observable universe, measuring about ≈10 billion light-years in length (the observable universe is about ≈93 billion ly in diameter). Its mass is estimated to be ≈2×10^19 M☉ or ≈20 quintillion solar masses or ≈3.977×10^46 t aka ≈39 quattuordecillion 770 tredecillion metric tons. However, it takes ≈5028.92 Hercules-Corona Borealis Great Walls to reach the same mass as the mass of ordinary matter in the observable universe.

The universe is a big guy. But we can only estimate it based on what we’ve discovered so far and what’s within the limits of our [particle horizon](https://en.wikipedia.org/wiki/Particle_horizon), the boundary between the observable and the unobservable universe. Looking at you, dark matter 🫵🏽🧐. Or [strange matter](https://en.wikipedia.org/wiki/Strange_matter). Or any other mattering matter.