# How massive is the universe?

##### 1 Answer

It's hard to say, but it's really really big.

#### Explanation:

If you mean the universe as in everything around us, including outside of our galaxy, then its unknown. The universe is ever-expanding and growing, so we will never have an exact measurement.

Currently our *'observable universe'* is **28 billion light-years in diameter** . When you calculate that to kilometers, well you get a really really big number.

One Astronomical Unit, or AU for short, is 150 million km. And in a single light year there is 63241.1 AU. And we have 28 billion light-years in diameter that we can see.

So! Here is the math!

63241.1AU x 28,000,000,000ly = 1,770,750,800,000,000AU

1,770,750,800,000,000AU x 150,000,000km = 2.6561262e+23

So our current observable universe is **2.6561262e+23km.**

Here is where someone asked a similar question with the same answer!