Cosmic Scale
Observable Universe
Everything we can ever see · You are at the centre
How big is Observable Universe?
Observable Universe is about 93 billion light-years across.
See Observable Universe in 3D, at true scale
The observable universe is the sphere around us from which light has had time to arrive since the Big Bang. It is not the whole universe — only the part we can, even in principle, ever see.
At a glance
| Diameter | 93 billion light-years |
|---|---|
| Mass | 1.50 × 10⁵³ kg |
| Diameter compared with Earth | 6.9 × 10¹⁹ × Earth |
| Age | 13.8 billion years |
| Galaxies | Up to 2 trillion |
| Ordinary matter | Only 5% of the contents |
Good to know
- The edge is 46.5 billion light-years away even though light has travelled for 13.8 billion years — space expanded while the light was in flight.
- The oldest light we can see is the cosmic microwave background, released 380,000 years after the Big Bang.
- Galaxies are arranged in a web of filaments and voids, shaped by dark matter.
- Next smaller: Hercules–Corona Borealis Great Wall · 10 billion light-years