Moon
The Moon is Earth’s natural satellite and the brightest large object in Earth’s night sky.
How big is it?
3,475 km · mean diameter
Mean diameter · approximate
A little perspective
Moon vs Earth: diameter comparison
The mean diameter of Earth is about 3.67 times the mean diameter of the Moon.
The Moon is Earth’s natural satellite and the brightest large object in Earth’s night sky.
Earth is the rocky planet on which we live and the third planet from the Sun.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions.
Measurements, assumptions & sources +
Moon
Mean diameter: 3,475 km; approximate.
Rounded mean-radius model of Moon. The derived area and volume describe a sphere; surface terrain and flattening are omitted.
NASA JPL — Planetary satellite physical parameters
The marked mean diameter is calibrated. Unmeasured illustration details are representative.
Earth
Mean diameter: 12,740 km; approximate.
Mean-radius spherical model for Earth; actual shape is not perfectly spherical.
NASA JPL — planetary physical parameters
The marked mean 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 3,475 km
We compare the mean diameter of the Moon. This is an estimate; check the notes for its rounding and uncertainty.
Rounded mean-radius model of Moon. The derived area and volume describe a sphere; surface terrain and flattening are omitted.
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 |
|---|---|---|---|
| 3,475 km | Not recorded | approximate | |
| 37,930,000 km² | Not recorded | derived | |
| 2.197 × 10¹⁰ km³ | Not recorded | derived | |
| 7.346 × 10¹⁹ t | Not recorded | derived | |
| 1.62 m/s² | 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 spacePluto2,377 kmMean diameterPluto is a dwarf planet in the Kuiper Belt, composed of rock and ice and orbiting the Sun.
Around the same scalePlaces and natural featuresVolga3,530 kmApproximate main-channel lengthThe Volga is a river in central Russia, running from the Valdai Hills to the Caspian Sea.
Nearest higher valuePlanets, moons and spaceIo3,643 kmMean diameterIo is a natural satellite of Jupiter, covered with active volcanoes and sulphur deposits.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- NASA JPL — Planetary satellite physical parametersPublished mean radii and gravitational parameters GM. Spherical areas, volumes, masses and local gravity are explicitly derived.
- NASA — Earth and Moon by the numbersMean radius and average orbital distance; rounded values.
More ways to see it
Curated comparisons
There’s always another scale
Follow your curiosity.
SpaceEarth12,740 kmEarth is the rocky planet on which we live and the third planet from the Sun.SpacePluto2,377 kmPluto is a dwarf planet in the Kuiper Belt, composed of rock and ice and orbiting the Sun.
SpaceJupiter139,800 kmJupiter is a giant planet composed mainly of hydrogen and helium, orbiting the Sun beyond the asteroid belt.SpaceIo3,643 kmIo is a natural satellite of Jupiter, covered with active volcanoes and sulphur deposits.
SpaceEuropa3,122 kmEuropa is a natural satellite of Jupiter, with a smooth icy surface thought to cover a subsurface ocean.
SpaceTriton2,705 kmTriton is a natural satellite of Neptune, with a retrograde orbit and a surface of frozen nitrogen.
SpaceCallisto4,821 kmCallisto is a natural satellite of Jupiter, with a heavily cratered icy surface.
SpaceMercury4,879 kmMercury is a rocky planet orbiting closest to the Sun in the Solar System.