I read online that a Sandworm can grow to 450 meters long, and there are legends of worms up to 1000 meters long. The same article also stated that Sandworms are territorial and so will claim an area of desert as their own.

That got me to thinking, just how big is the planet Dune in comparison to Earth and has anyone worked out from its size how many sandworms could be present on the planet at any one time?

  • 1
    As they are often used for transport over long distances,I think the population is quite high; from the books, a simple thumper put anywhere will call a worm quickly.
    – Max
    Feb 18, 2020 at 12:08

2 Answers 2


1.6 Million*

The only real information we have to go on is a line by Dr. Kynes about the size of a worm's territory. From Dune:

“Big ones may control three or four hundred square kilometers. Small ones—”

According to the non-canonical Dune Encyclopedia, Arrakis has a radius of approximately 6,128 km, giving it a total surface area of 4.72×108 km2.

So, as a really rough estimate, let's make a few assumptions:

  1. Dr. Kynes never finished his statement, but lets say for argument that an average-sized worm's territory to be 250 square kilometres.
  2. Fifteen per cent of Arrakis' surface is inaccessible to worms (the Imperial Basin, the "wormline" surrounding the north pole, rock outcroppings, etc). This would leave a "worm-friendly" surface area of approximately 4.012×108 km2.
  3. Let's exclude altogether other stages of the worm lifecycle (sandtrout, etc), post-spice blow areas where they could be several new worms, as well as the "stunted worms" kept by the Fremen.
  4. We'll also ignore instances of contested territories and rare occurrences of multiple worms rampaging after shield generators and the like, and the fact that these territories are probably highly fluid and ever-changing as worms mature and move about.

Using our extremely broad reasoning, we could say that:

401,200,000 / 250 = 1,604,800 worm territories of average size.

  • 4
    That is a great answer, thankyou.
    – Richard C
    Feb 18, 2020 at 15:01
  • 17
    @Vanguard3000 However, the appendix to Dune gives the distance between two cities. The map of Dune in Dune shows those two cities. If one turns the line between the cities to north-south one can see how many degrees of latitude it covered. Thus one can calculate the length of a degree of latitude and thus the circumference, diameters, and surface area of Dune. I did that calculation once and found that Dune should be smaller than Earth's Moon. Which seems improbable but is based on more canonical sources than the Dune Encyclopedia. Feb 18, 2020 at 15:53
  • 2
    @MichaelSeifert Which makes sense; Dune mentions Arrakis' gravity being ~0.9, and its mineral composition seems similar. Feb 18, 2020 at 20:37
  • 2
    400 km² for a 1 km long worm is like 1600 m² for a 2 m human. Which is a 40 m x 40 m area. A little garden. Seems very crowded if the whole planet is divided up like that! You could never leave your small garden because it's surrounded by the small gardens of other territorial worms on all sides. Feb 20, 2020 at 12:01
  • 3
    While burrowing through sand seems per se improbable (it doesn't sound any easier or less energy-intense than burrowing through rock ... are sandworms nuclear-powered?), how deep is the Sea of Sand? Can you have several layers of sandworm? Feb 20, 2020 at 18:52

To be technically correct, while being not at all helpful, at the time of God Emperor of Dune there was exactly one sandworm on Arrakis.

All other time periods, your mileage may vary.

  • 18
    And after the destruction of Arrakis, zero worms
    – Valorum
    Feb 18, 2020 at 12:05
  • 5
    I've downvoted. OP isn't asking for the worm population at any specific moment but rather how many works can be present theoretically
    – Valorum
    Feb 18, 2020 at 12:10
  • 3
    @Max no. The only spice in existence during this period was Leto's stockpile. Feb 18, 2020 at 14:16
  • 19
    @Valorum You just have to regard Leto as extremely territorial. The math still works out to 1.
    – Spencer
    Feb 18, 2020 at 14:52
  • 7
    @Valorum the question's title and body conflict as to what he's asking: "Roughly how large is the population of Sandworms?", which is point-in-time vs "how many sandworms could be present on the planet at any one time?"
    – RonJohn
    Feb 18, 2020 at 20:04

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