As the question title suggests, I'm looking to find out how long a human could live for if they didn't age in their sleep. Assume that this ability kicks in at about the age of 16 and they have complete control over when they sleep and how long they sleep for, but that they still need at least the regular human amount of sleep.

The people in question may also attempt to live for even longer by sleeping through car rides and other such events where they don't need to stay awake.

So, how long could they live if they slept for the normal amount of time?

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    $\begingroup$ Isn't this basic arithmetic you're asking us to do here? What other effects that are a bit more of a worldbuilding issue do you need help with? $\endgroup$ Commented May 17 at 21:48

1 Answer 1


EDIT: The question was edited after I answered, so the previous answer and the assumptions are below the line.

How long could they live if they slept for the normal amount of time? Our elderly that can live up to 116 years can now live to 149 years old (see below). Each year of life would add an additional 122 days of life.

How long could they live if they could control their sleep? As long as they like. If they are only awake 8 hours a day, they can add 243 days to their life each living year.

Previous answer:

  1. If a human can live, say maximum 116 years (let's keep the math simple), then you have 876,000 hours of "life" after 16. If you add an additional 8 hours to every day, you get 292,000 more hours, or 133 aging years after you've turned 16 (your elderly octogenarian would live to 149 years old instead of 116).

  2. Can you be more specific? I can't really sleep much more than 6 to 8 hours on average, if I try. Some people can do a little more, true. I supposed if you can induce sleep, you can sleep nearly forever after turning 16, because you are not aging, and you are being kept alive by machinery.


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