A Star Trek holodeck presents an illusion of a location to users who are inside the room.

When the party splits up each group sees that the other group has moved away, but in reality they're in a medium-sized room on the ship.

The assumption is that the holodeck tech is able to present a different illusion to each user.

So, how many real tangible users could fit inside a holodeck and not spoil the illusion? Could it be as small as the Da Vinci radius around a person?

Inspired by How can the holodeck in Star Trek: Generations exist around an exit?

Assume normal sized humans between 4 and 7 feet tall, with normal proportion armspans. Its reasonable to ignore extra senses like Geordi's visor or Seven's extras, or any sense that a non-human might possess.

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    This is a great question. Something to keep in mind: Star Trek: Insurrection introduces us to holoships, which are used to transport populations. They're quite a bit larger in size than your typical Enterprise holodeck. There's also the episode "Homeward" (Episode 7x13) that may help a potential answer.
    – Ellesedil
    Apr 4, 2017 at 3:46
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    My guess would be N = X ÷ (π * (avgA ÷ 2)²), where X is the floor space of the Holodeck, and avgA is the average armspan of the people in the room. This equation represents the approximate number of people, N, that can fully extend their arms and spin around in a circle without touching the walls or another person. Apr 4, 2017 at 10:46
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    Sight and Sound are fairly easy to fool, as is smell if you can localise the effect to each person, which I imagine will be more than possible by then, considering it's achievable now. Touch, on the other hand, especially in a Holodeck environment, is more difficult to fool, and if you accidentally touch something that shouldn't be there, it'll break your immersion. Of course, this is mostly a guess, since I don't really understand how a Holodeck works and everything I've said is possibly wrong. Apr 4, 2017 at 10:48
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    I guess the minimum distance between users (players?) depends on how much buffer the technology requires. Imagine a boat and one player gets splashed. Holodeck needs to replicate stuff (water spray off waves) and to remove it again before it hits another player who is "inside the cabin" Likewise, some depth would be needed to "catch" and muffle sounds, and to visually show the right view to each player.
    – Criggie
    Apr 4, 2017 at 11:59
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    They get a whole village in one on the Enterprise in Homeward, although I’m not sure how many people that is. Apr 11, 2017 at 22:21

1 Answer 1


The holodeck is the same size, only granting an illusion of a larger area. You would only be able to fit the same number of people into an empty holodeck as you would one that was turned on. Since the actual rooms vary in size based on ship-but are using standard cube measurements- W x L x V= answer. If it has a length of 20 feet and width of 20 feet, you get an area of 400 feet. With a height of 20 feet, you now have 8000 cubed feet for a 20 x 20 x 20 room. Since you're asking the number of people who can fill up the room and maintain the illusion... a person averages 68inches or 5feet 8inches-but giving them a total of 7 feet for extra space. To give the illusion of say a class room with at least 2 floors-you could put 1140+ people in that room. I'm sure a better math person can get you a better version, but the idea is there. You can't really do 3 floors without squeezing in people laying down, but if you did-you could add another 570+.

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