Putting the Size of the Observable Universe in Perspective. The age of the universe is about 13.75 billion years. The diameter of the observable universe is estimated at about 28 billion parsecs (

**93 billion light-years**).In this manner, how big is the visible universe?

If inflation occurred at a constant rate through the life of the universe, that same spot is 46 billion light-years away today, making the diameter of the observable universe a sphere around

**92 billion light-years**. [How old is the universe and how do we know this?

Knowing the current speeds and distances to galaxies, coupled with the rate at which the

**universe**is accelerating, allows us to calculate how long it took for them to reach their current locations. The answer is about 14 billion years. The second method involves measuring the**ages**of the oldest star clusters.