Scale Explorer

Space

How big is Olympus Mons?

Olympus Mons · Shield volcano on Mars

Height
22–27 km 14–17 mi range
Base diameter
at least 600 km 370 mi approx.
Basal scarp height
up to 6 km 20,000 ft maximum
Show
Human, Olympus Mons, Moon, Mars drawn to the same scaleHuman: height 1.61–1.75 m (too small to see at this scale). Olympus Mons: height 22–27 km. Moon: diameter 3,475 km. Mars: equatorial diameter 6,792 km.Human: 1.61–1.75 m (too small to see at this scale)Olympus Mons: 22–27 kmMoon: 3,475 kmMars: 6,792 kmMars6,792 kmMoon3,475 kmHuman1.61–1.75 m · too small to seeOlympus Mons22–27 km

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 Olympus Mons with something else →

Zoom out from an average adult to Olympus Mons

Olympus Mons is too big to show next to an average adult in one picture, so here it is in 6 steps. Each step is drawn to its own scale and zooms out from the step before.

  1. Step 1 of 6 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 6 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 6 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 6 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 6 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 6 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.

Dimensions

MeasurementMetricImperialNotesSource
Height 22–27 km 14–17 mi 22 km average elevation (ESA, Mars Express) to 27 km high (NASA Viking mosaic caption); the figures use different reference levels. Range: varies [2] [1]
Base diameter at least 600 km at least 370 mi Width at the base, stated as 'over 600 kilometers'. Approximate [1]
Basal scarp height up to 6 km up to 20,000 ft Cliff ringing the volcano. Maximum [1]

About Olympus Mons

Olympus Mons is a shield volcano on Mars and the largest known volcano in the solar system. Its height is quoted from about 22 km (ESA) to 27 km (NASA), roughly two and a half to three times Mount Everest's height above sea level. It is over 600 km wide at the base, ringed by a cliff up to 6 km high, and topped by a caldera about 3 km deep.

  • NASA's Viking mosaic caption describes Olympus Mons as 27 km high and over 600 km wide at the base, surrounded by a scarp up to 6 km high. [1]
  • ESA gives Olympus Mons an average elevation of 22 km, with a summit caldera about 3 km deep. [2]
  • NASA's Mars facts page says the volcano's base covers an area as large as the state of Arizona. [3]

How many fit?

  • ≈ 13,000–17,000 × Human · height lined up end to end match the Olympus Mons · height
  • ≈ 5.8–7.2 × Mount Fuji · height above sea level lined up end to end match the Olympus Mons · height

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

  • 13,000–17,000× Olympus Mons is about 13,000–17,000 times as high as an average adult is tall. See side by side
  • 5.8–7.2× Olympus Mons is about 5.8–7.2 times as high as Mount Fuji is tall. See side by side
  • 2.5–3.1× Olympus Mons is about 2.5–3.1 times as high as Mount Everest is tall. See side by side
  • 1/130–160 The Moon is about 130–160 times as wide as Olympus Mons is high. See side by side
  • 1/250–310 Mars is about 250–310 times as wide as Olympus Mons is high. See side by side
  • 1/470–580 Earth is about 470–580 times as wide as Olympus Mons is high. See side by side

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

Notes on these figures

  • Height depends on the reference level: ESA's 22 km is an elevation above the Mars reference surface, while NASA's Viking caption gives 27 km.
  • NASA's Mars facts page gives a much larger 'more than 25 miles (that's more than 132,000 feet, or 40 kilometers) tall from base to summit'; this is far above the other agency figures and is not used in the range.
  • The base width is stated only as 'over 600 kilometers', so 600 km is a lower bound.

Sources

  1. NASA Science (Photojournal), Olympus Mons (PIA00300). Accessed 25 September 2026.
  2. European Space Agency, Olympus Mons - the caldera in close-up. Accessed 25 September 2026.
  3. NASA Science, Mars: Facts. Accessed 25 September 2026.

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