Observable universe
The observable universe is the region from which light or other signals have had time to reach us since the early universe.
28.21 GpcDiameterWorlds apart
Observable universe vs Local Group
What are they, and what does the difference actually look like?
Two things. One honest scale.
Meet the pair
What these two things are
Local Group
The Local Group is a collection of galaxies that includes the Milky Way, Andromeda, and several smaller galaxies.
3.066 MpcDiameterObservable universe has about 9,200 times the diameter of Local Group.
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Observable universe28.21 GpcDiameter
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Local Group3.066 MpcDiameter
Inset ×3,200Local Group is too small to see clearly at this scale. The ring marks its position; only the inset is enlarged.
Measurements, assumptions & sources +
Observable universe
About 92 billion light-years across in present-day comoving distance. Space expanded while the light travelled. The 13.8-billion-year age is a time, not its radius divided by light speed. The total universe may be far larger, possibly infinite.
NASA — How big is space? (2025)
The marked diameter is calibrated. Unmeasured illustration details are representative.
Local Group
A rounded 10 million light-year span for the neighbourhood of galaxies. Galaxy groups have no solid edge.
Defined examples — our methodology
The marked diameter is calibrated. Unmeasured illustration details are representative.
Change the comparison
Put something else beside it.
Measurement details
Why these numbers?
The visual compares diameter with diameter. The records below preserve each value’s basis and caveats.
Observable universe
28.21 GpcDiameter · cosmological estimate
About 92 billion light-years across in present-day comoving distance. Space expanded while the light travelled. The 13.8-billion-year age is a time, not its radius divided by light speed. The total universe may be far larger, possibly infinite.
Local Group
3.066 MpcDiameter · rounded reference
A rounded 10 million light-year span for the neighbourhood of galaxies. Galaxy groups have no solid edge.
- Comparing
- Diameter ↔ Diameter
- Relative size
- Observable universe is larger on this measurement by a factor of about 9,200.
How to read the visual
The labelled spans and stored measurements determine the scale; unmeasured illustration details do not.
- Observable universe is labelled cosmological estimate; treat the displayed value as a comparison anchor rather than false precision.
- Local Group is labelled rounded reference; treat the displayed value as a comparison anchor rather than false precision.
There’s always another scale
Follow your curiosity.
SpaceObservable universe28.21 GpcThe observable universe is the region from which light or other signals have had time to reach us since the early universe.SpaceLocal Group3.066 MpcThe Local Group is a collection of galaxies that includes the Milky Way, Andromeda, and several smaller galaxies.
SpaceMilky Way30.66 kpcThe Milky Way is a spiral galaxy containing hundreds of billions of stars, including our Solar System.
Fundamental physicsPlanck length1.616 × 10⁻³⁵ mThe Planck length is a scale formed from fundamental physical constants.
SpaceEarth–Sun distance1 AUThe Earth–Sun distance, or astronomical unit, is the standard measure of separation between Earth and the Sun used in astronomy.Side by side
Another point of view.
