The Moon is much smaller than Earth: it’s about 1/4 as wide, has about 1/50 the volume, and only about 1/81 the mass of our planet.

Quick Scoop

If you shrank Earth down to the size of a large basketball , the Moon would be roughly the size of a tennis ball orbiting around it. That’s the kind of size difference we’re talking about when people ask, “how big is the moon compared to earth.”

Basic Size Comparison

  • Moon diameter ≈ 3,474–3,475 km.
  • Earth diameter ≈ 12,742–12,800 km.
  • That makes the Moon about 27% of Earth’s diameter (roughly one-quarter).
  • You could line up about four Moons across the width of Earth.
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<table>
  <thead>
    <tr>
      <th>Property</th>
      <th>Earth</th>
      <th>Moon</th>
      <th>Moon vs Earth</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Diameter</td>
      <td>≈ 12,742 km[web:3][web:5]</td>
      <td>≈ 3,474–3,475 km[web:1][web:3][web:5][web:9]</td>
      <td>≈ 27% (about 1/4)[web:1][web:3][web:5]</td>
    </tr>
    <tr>
      <td>Volume</td>
      <td>≈ 1.08 × 10¹² km³[web:5]</td>
      <td>≈ 2.20 × 10¹⁰ km³[web:5]</td>
      <td>≈ 1/49 of Earth[web:5]</td>
    </tr>
    <tr>
      <td>Mass</td>
      <td>81× Moon’s mass[web:1][web:5][web:9]</td>
      <td>≈ 1.2% of Earth’s mass[web:1][web:9]</td>
      <td>Moon is 1/81 as massive[web:1][web:9]</td>
    </tr>
    <tr>
      <td>Surface area</td>
      <td>≈ 510 million km²[web:3]</td>
      <td>≈ 38 million km²[web:1][web:3][web:9]</td>
      <td>≈ 7–8% of Earth[web:3]</td>
    </tr>
  </tbody>
</table>

How It Looks In Everyday Terms

  • If Earth were a nickel , the Moon would be about the size of a coffee bean.
  • The Moon’s diameter is similar to the width of the continental United States or mainland Australia.
  • The Moon’s entire surface area is a bit smaller than the continent of Asia.

So when you look up at the sky, you’re seeing a world that could just about fit on one of Earth’s big continents.

Gravity And “Feel” Of The Size

Because the Moon is so much less massive, its surface gravity is only about 1/6 of Earth’s.

That’s why astronauts in old footage appear to bounce as they walk; they’re on a world that’s small both in size and in pull.

Forum‑Style Takeaway And TL;DR

“So… how big is the Moon compared to Earth?”
Think “tennis ball vs basketball,” or “coffee bean vs nickel” — about one- quarter as wide, ~1/50 the volume, and ~1/80 the mass.

TL;DR: The Moon is about 27% as wide as Earth, has only about 7–8% of Earth’s surface area, around 1/49 of its volume, and roughly 1/81 of its mass.

Information gathered from public forums or data available on the internet and portrayed here.