Scale Explorer

Space

How big is Mars?

Mars

Equatorial diameter
6,792 km 4,220 mi
Mass
6.4169 × 10²³ kg 1.4147 × 10²⁴ lb
Volume
163.12 billion km³ 39.135 billion cu mi
Show
Human, Moon, Mars, Earth drawn to the same scaleHuman: height 1.61–1.75 m (too small to see at this scale). Moon: diameter 3,475 km. Mars: equatorial diameter 6,792 km. Earth: equatorial diameter 12,756 km.Human: 1.61–1.75 m (too small to see at this scale)Moon: 3,475 kmMars: 6,792 kmEarth: 12,756 kmEarth12,756 kmMars6,792 kmMoon3,475 kmHuman1.61–1.75 m · too small to see

Human is too small to see at this scale and is marked with ▲.

Everything is drawn to the same scale, standing on the same ground line. Silhouettes are simplified outlines scaled to the measured dimension. A faded outline shows the top of a size range.

Compare Mars with something else →

Zoom out from an average adult to Mars

Mars is too big to show next to an average adult in one picture, so here it is in 7 steps. Each step is drawn to its own scale and zooms out from the step before.

  1. Step 1 of 7 Human → Megalodon

    A megalodon is about 8.6–15 times as long as an average adult is tall.

    Human, Megalodon drawn to the same scaleHuman: height 1.61–1.75 m. Megalodon: maximum length (estimates) 15–24.3 m.Human: 1.61–1.75 mMegalodon: 15–24.3 mMegalodon15–24.3 mHuman1.61–1.75 m
    Step 1: Human and Megalodon at the same scale.

  2. Step 2 of 7 Megalodon → Great Pyramid of Giza

    The Great Pyramid of Giza is about 5.6–9.1 times as tall as a megalodon is long.

    Megalodon, Great Pyramid of Giza drawn to the same scaleMegalodon: maximum length (estimates) 15–24.3 m. Great Pyramid of Giza: current height ≈ 137 m.Megalodon: 15–24.3 mGreat Pyramid of Giza: ≈ 137 mGreat Pyramid of Giza≈ 137 mMegalodon15–24.3 m
    Step 2: Megalodon and Great Pyramid of Giza at the same scale.

  3. Step 3 of 7 Great Pyramid of Giza → Golden Gate Bridge

    The Golden Gate Bridge is about 20 times as long as the Great Pyramid of Giza is tall.

    Great Pyramid of Giza, Golden Gate Bridge drawn to the same scaleGreat Pyramid of Giza: current height ≈ 137 m. Golden Gate Bridge: total length 2,737 m.Great Pyramid of Giza: ≈ 137 mGolden Gate Bridge: 2,737 mGolden Gate Bridge2,737 mGreat Pyramid of Giza≈ 137 m
    Step 3: Great Pyramid of Giza and Golden Gate Bridge at the same scale.

  4. Step 4 of 7 Golden Gate Bridge → Mount Everest

    Mount Everest is about 3.2 times as tall as the Golden Gate Bridge is long.

    Golden Gate Bridge, Mount Everest drawn to the same scaleGolden Gate Bridge: total length 2,737 m. Mount Everest: height above sea level 8,848.86 m.Golden Gate Bridge: 2,737 mMount Everest: 8,848.86 mMount Everest8,848.86 mGolden Gate Bridge2,737 m
    Step 4: Golden Gate Bridge and Mount Everest at the same scale.

  5. Step 5 of 7 Mount Everest → Mauna Kea

    Mauna Kea is about 1.2 times as tall as Mount Everest.

    Mount Everest, Mauna Kea drawn to the same scaleMount Everest: height above sea level 8,848.86 m. Mauna Kea: height from ocean floor to summit ≈ 10,211 m.Mount Everest: 8,848.86 mMauna Kea: ≈ 10,211 mMauna Kea≈ 10,211 mMount Everest8,848.86 m
    Step 5: Mount Everest and Mauna Kea at the same scale.

  6. Step 6 of 7 Mauna Kea → Olympus Mons

    Olympus Mons is about 2.2–2.6 times as high as Mauna Kea is tall.

    Mauna Kea, Olympus Mons drawn to the same scaleMauna Kea: height from ocean floor to summit ≈ 10,211 m. Olympus Mons: height 22–27 km.Mauna Kea: ≈ 10,211 mOlympus Mons: 22–27 kmOlympus Mons22–27 kmMauna Kea≈ 10,211 m
    Step 6: Mauna Kea and Olympus Mons at the same scale.

  7. Step 7 of 7 Olympus Mons → Mars

    Mars is about 250–310 times as wide as Olympus Mons is high.

    Olympus Mons, Mars drawn to the same scaleOlympus Mons: height 22–27 km. Mars: equatorial diameter 6,792 km.Olympus Mons: 22–27 kmMars: 6,792 kmMars6,792 kmOlympus Mons22–27 km
    Step 7: Olympus Mons and Mars at the same scale.

Dimensions

MeasurementMetricImperialNotesSource
Equatorial diameter 6,792 km 4,220 mi Diameter at the equator [2]
Mass 6.4169 × 10²³ kg 1.4147 × 10²⁴ lb Source states 0.64169 × 10²⁴ kg [1]
Volume 163.12 billion km³ 39.135 billion cu mi NASA fact sheet lists this as 10^10 km³ units [1]

About Mars

Mars is the fourth planet from the Sun. At 6,792 km across the equator, it is roughly half as wide as Earth. Its mass is about 6.42 × 10^23 kg, a little over a tenth of Earth's.

  • The equatorial radius of Mars is 3,396.2 km and its volumetric mean radius is 3,389.5 km. [1]
  • NASA's fact sheet puts the mass of Mars at 0.107 times Earth's. [1]
  • NASA describes Mars as having a radius of 2,106 miles (3,390 km), about half the size of Earth. [3]

How many fit?

  • ≈ 4 million × Human · height lined up end to end match the Mars · equatorial diameter
  • ≈ 7.7 × 10²¹ × Human · body mass on the scales weigh as much as Mars · mass
  • ≈ 2 × Moon · diameter lined up end to end match the Mars · equatorial diameter
  • ≈ 8.7 × Moon · mass on the scales weigh as much as Mars · mass
  • ≈ 7.4 × Moon · volume packed inside, by volume fill Mars · volume

Counts divide one sourced figure by another. "End to end" uses each object's main measurement; weight and volume rows appear only when both figures are sourced.

How it compares

Factors compare the equatorial diameter of Mars with each object’s own main measurement (height for a human). Where a size varies, the factor is given as a range.

Sources

  1. NASA Space Science Data Coordinated Archive, Mars Fact Sheet. Accessed 24 September 2026.
  2. NASA Space Science Data Coordinated Archive, Planetary Fact Sheet - Metric. Accessed 24 September 2026.
  3. NASA Science, Mars: Facts. Accessed 24 September 2026.

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