Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Percent Ordinary Matter
Name: Dan
Status: student
Age: N/A
Location: N/A
Country: N/A
Date: N/A

What percentage of the universe is made of ordinary matter?


I am not exactly sure what you are trying to ask, so I will take a couple stabs.

Are you asking what percentage of the volume of the universe contains matter?

The answer to that question is not well understood by scientists. The rate of expansion of the universe indicates there should be more mass than we observe through telescopes. Thus, some scientists have predicted 'dark matter' that we cannot see, or other solutions, to explain this apparent contradiction. So, we are not really sure how much matter there is, and if this dark matter exists, where it is or how much space it takes up. However, there is a lot more 'empty space' (it is not really empty, but ...) where we do not see stars and galaxies than where we do see them.

Are you asking what is the ratio between the matter we can see and the matter we think should be there (e.g. dark matter)?

If this is your question, estimates range up to 95% of the matter in the universe being 'dark' matter. There is also 'dark energy' which could be three times more than that as well. Scientists do not have a great grasp on this yet -- they are working on it though.

I hope these are helpful. If you're asking something else, reply back and let me know what you meant.


Burr Zimmerman

Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory