I would like to know why people, websites, forums, etc. all claim that Trantor from Foundation is larger than Earth.

In the book, it's clearly stated that Trantor's surface area is 19,230,000,000 hectares.

Earth has a surface area of 51,001,000,000 hectares, so Trantor isn't even half its size.

  • 4
    Hi, welcome to SF&F. Please write a more civil question. You should also cite the exact quote you're using as a reference.
    – DavidW
    Nov 24 at 2:24
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    FWIW, the 130% number simply falls out of a comparison of land area. 75M mile^2 is about 194M km^2; the land area of Earth is approximately 149M km^2, and 194/149 = 1.3 (130%). We have no idea of either the total surface area of Trantor or the percentage covered by oceans, so there's no other useful comparison to draw.
    – DavidW
    Nov 24 at 3:35
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    The book does explicitly say it's talking about land area only: "All the land surface of Trantor, 75,000,000 square miles in extent, was a single city." Not sure why Rusty put it in hectares (and with extra digits that aren't actually correct if you translate 75 million square miles to hectares)--different edition or translation?
    – Hypnosifl
    Nov 24 at 5:10
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    Attempted troll seemingly results in somewhat-useful clarification. Stack Exchange has life in it yet! Nov 24 at 14:01
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    @DannyMcG - You can always have a nosey at the timeline and edit history
    – Valorum
    Nov 24 at 16:46

The fact cited in the wiki is about the land surface of Trantor, not the overall surface area of the planet. The relevant quotes from Foundation give us the land area:

Its urbanization, progressing steadily, had finally reached the ultimate. All the land surface of Trantor, 75,000,000 square miles in extent, was a single city. The population, at its height, was well in excess of forty billions.


But Trantor is not all land; it has oceans as well:

Trantor is tunneled over a mile down. It's like an iceberg. Nine-tenths of it is out of sight. It even works itself out a few miles into the sub-ocean soil at the shorelines.

Foundation, Chapter 3

Without knowing the fraction of Trantor's surface covered by oceans, we can only compare Trantor to Earth's land area, which is approximately 149 million km2. (148 940 000 km2 per Wikipedia.)

The given 75 million square miles land area for Trantor is about 194 million km2 (to the same amount of precision). So the relative amount of land area is 194 / 149 = 1.30, or 130%, just as stated. Note that this is not a comparison of the relative sizes of the planets, since we have no idea if Trantor is only 20% ocean, which would give it a total surface area less than half of Earth, or if it's 80% ocean, giving it nearly twice Earth's surface area.

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