# What is the amount of dark energy in the Universe, in joules?

I'm toying with an idea, and need absolute amounts of dark energy. I'd also like the same for dark matter. If these values are not estimated, why not?

• Thanks to all for the info. Very helpful and informative. I now move from crazy idea to crazy calculation. I like absolute numbers. – Incredible II Feb 13 '16 at 16:44

## 1 Answer

The dark energy density in the universe is about $7 \times 10^{-30}$g/cm$^3$ on average according to Wikipedia. This is uniform through out the Hubble volume of the entire universe i.e. the volume of the universe with which we are in causal contact. The Hubble volume is $10^{31} \ ly^3$ i.e. cubic light years. This gives $8.46732 \times 10^{84}$ cm$^3$ as the volume of the universe. Using the mass-energy equivalence, you find that the total dark energy content in the entire universe is around $10^{69}$ Joules, which is truly massive. This is in agreement with the result here.

• Dear @RobJeffries, thank you for your comment. Yes, of course, this depends on whether there are also local field contributions from say scalar fields which can lead to non-uniformities. I wanted to make the answer as simple as possible but I have now included your comments in my answer. Thanks :) – user106422 Feb 13 '16 at 11:08
• Actually now I think it is made more complicated. I retract my comment. Just say that the average density is .... My original comment was confusing dark matter and dark energy, apologies. – Rob Jeffries Feb 13 '16 at 11:26