Scale Explorer

Structures

How tall is the Hoover Dam?

Hoover Dam

Height
221.4 m 726.4 ft
Crest length
379.2 m 1,244 ft
Width at top (crest)
13.7 m 45 ft
Thickness at base
201 m 660 ft
Show
Human, Big Ben (Elizabeth Tower), Starship, Hoover Dam drawn to the same scaleHuman: height 1.61–1.75 m. Big Ben (Elizabeth Tower): height of the elizabeth tower 96 m. Starship: full-stack height ≈ 124 m. Hoover Dam: height 221.4 m.Human: 1.61–1.75 mBig Ben (Elizabeth Tower): 96 mStarship: ≈ 124 mHoover Dam: 221.4 mHoover Dam221.4 mStarship≈ 124 mBig Ben (Elizabeth Tower)96 mHuman1.61–1.75 m
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 Hoover Dam with something else →

Zoom out from an average adult to the Hoover Dam

The Hoover Dam is too big to show next to an average adult in one picture, so here it is in 3 steps. Each step is drawn to its own scale and zooms out from the step before.

  1. Step 1 of 3 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 3 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 3 Great Pyramid of Giza → Hoover Dam

    The Hoover Dam is about 1.6 times as tall as the Great Pyramid of Giza.

    Great Pyramid of Giza, Hoover Dam drawn to the same scaleGreat Pyramid of Giza: current height ≈ 137 m. Hoover Dam: height 221.4 m.Great Pyramid of Giza: ≈ 137 mHoover Dam: 221.4 mHoover Dam221.4 mGreat Pyramid of Giza≈ 137 m
    Step 3: Great Pyramid of Giza and Hoover Dam at the same scale.

Dimensions

MeasurementMetricImperialNotesSource
Height 221.4 m 726.4 ft Foundation rock to the roadway on the crest; parapet towers and ornaments rise a further 40 ft [1]
Crest length 379.2 m 1,244 ft Length of the dam along its crest [2]
Width at top (crest) 13.7 m 45 ft Thickness of the dam at its top, where the road runs [3]
Thickness at base 201 m 660 ft Upstream-to-downstream thickness at the base [3]

About the Hoover Dam

Hoover Dam is a concrete arch-gravity dam in Black Canyon on the Colorado River, on the Arizona-Nevada state line. It was built between 1931 and 1936 and holds back Lake Mead. In cross-section it tapers like an axe head, from 660 ft thick at its base to 45 ft at the top, where a road crosses the crest.

  • The dam itself contains three and one-quarter million cubic yards of concrete; the dam, powerplant and associated works together contain 4,360,000 cubic yards. [1]
  • Hoover Dam weighs more than 6,600,000 tons. [1]
  • The towers and ornaments on the parapet rise 40 feet above the crest. [1]
  • The maximum water pressure at the base of the dam is 45,000 pounds per square foot. [1]
  • As many as 20,000 vehicles a day drive across the 45 ft wide top of the dam between Nevada and Arizona. [4]
  • The final bucket of concrete was placed in the main dam on May 29, 1935. [3]

How many fit?

  • ≈ 130 × Human · height lined up end to end match the Hoover Dam · 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

  • 130× The Hoover Dam is about 130 times as tall as an average adult. See side by side
  • 1.2× The Hoover Dam is about 1.2 times as tall as the Gateway Arch. See side by side
  • 1/1.2 The Titanic is about 1.2 times as long as the Hoover Dam is tall. See side by side
  • 1/1.6 A giant cruise ship is about 1.6 times as long as the Hoover Dam is tall. See side by side
  • 1/2.4 One World Trade Center is about 2.4 times as tall as the Hoover Dam. See side by side
  • 1/3.7 The Burj Khalifa is about 3.7 times as tall as the Hoover Dam. See side by side

Factors compare the height of the Hoover Dam 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

  • Reclamation pages give different concrete totals: 3.25 million cubic yards in the dam alone and 4,360,000 cubic yards including the powerplant and associated works (FAQ); 4,400,000 cubic yards for the dam, powerplant and associated structures (history and project-data pages); and '4 1/2 million cubic yards' (Kid Facts page).
  • The weight is given only as 'more than 6,600,000 tons', with no unit stated (probably short tons), so it is recorded as a fact rather than a measure.
  • Reclamation's project-data page confirms the headline dimensions independently of the FAQ and history pages: structural height 726.4 ft, crest length 1,244 ft, crest width 45 ft and base width 660 ft.
  • Reclamation describes the dam type in three ways: 'concrete arch-gravity' (FAQ), 'concrete gravity arch' (history page) and 'concrete thick arch' (project-data page).

Sources

  1. US Bureau of Reclamation, Hoover Dam - Frequently Asked Questions: The Dam. Accessed 24 September 2026.
  2. US Bureau of Reclamation, Hoover Dam - Reclamation project data (dimensions). Accessed 24 September 2026.
  3. US Bureau of Reclamation, The Boulder Canyon Project: Hoover Dam (history). Accessed 24 September 2026.
  4. US Bureau of Reclamation, Hoover Dam - Kid Facts. Accessed 24 September 2026.

Related objects