Milky Way
The Milky Way is a spiral galaxy containing hundreds of billions of stars, including our Solar System.
Also known as: our galaxy
How big is it?
30.66 kpc across
Diameter · approximate
A little perspective
Milky Way vs Andromeda galaxy: diameter comparison
The diameter of the Andromeda galaxy is about 2.6 times the diameter of the Milky Way.
The Milky Way is a spiral galaxy containing hundreds of billions of stars, including our Solar System.
The Andromeda galaxy, also called M31, is the nearest large spiral galaxy to the Milky Way.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
Measurements, assumptions & sources +
Milky Way
Diameter: 30.66 kpc; approximate.
A rounded 100,000 light-year span of the stellar disk. Faint stars and the dark-matter halo extend farther; galaxies have no crisp rim.
The marked diameter is calibrated. Unmeasured illustration details are representative.
Andromeda galaxy
Diameter: 79.72 kpc; approximate.
The 260,000 light-year extent is NASA’s ultraviolet-view reference. Diameters measured with another wavelength or brightness threshold differ.
The marked diameter is calibrated. Unmeasured illustration details are representative.
Use the visual comparison to explore its scale, then check the measurements and sources.
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Choose a suggestion to redraw the comparison, or open its page to learn what it is.
Why this measurement?
Why we use 30.66 kpc
We compare the diameter of the Milky Way. This is an estimate; check the notes for its rounding and uncertainty.
A rounded 100,000 light-year span of the stellar disk. Faint stars and the dark-matter halo extend farther; galaxies have no crisp rim.
The marked horizontal span follows the measured feature, not the edges of the image. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 30.66 kpc | Not recorded | approximate |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valuePlanets, moons and spaceDistance to the galactic centre7.972 kpcDistanceThis is the distance from the Solar System to the centre of the Milky Way galaxy.
Nearest higher valuePlanets, moons and spaceAndromeda galaxy79.72 kpcDiameterThe Andromeda galaxy, also called M31, is the nearest large spiral galaxy to the Milky Way.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- NASA — GalaxiesThe Milky Way stellar disk spans more than 100,000 light-years; 100,000 ly is our deliberately rounded scale anchor.
More ways to see it
Curated comparisons
There’s always another scale
Follow your curiosity.
SpaceSun1,391,000 kmThe Sun is the star at the centre of the Solar System.SpaceDistance to the galactic centre7.972 kpcThis is the distance from the Solar System to the centre of the Milky Way galaxy.SpaceAndromeda galaxy79.72 kpcThe Andromeda galaxy, also called M31, is the nearest large spiral galaxy to the Milky Way.
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.SpaceDistance to Andromeda766.5 kpcThis is the distance between the Milky Way and the Andromeda galaxy, our nearest large galactic neighbour.
SpaceLocal Group3.066 MpcThe Local Group is a collection of galaxies that includes the Milky Way, Andromeda, and several smaller galaxies.
SpaceDistance to the Virgo Cluster16.56 MpcThis is the distance from the Milky Way to the Virgo Cluster, a nearby large cluster of galaxies.
SpaceLaniakea-scale region159.4 MpcLaniakea is a vast region of interconnected galaxy clusters defined by shared gravitational flows.