I'm trying to worldbuild and one of my creatures is a 3 foot tall humanoid and I have no idea what they should weigh.

Does anyone know how much they would weigh or a math equation I could use to figure it out?

Thanks in advance

  • 2
    $\begingroup$ Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. $\endgroup$
    – Community Bot
    Sep 13 at 5:07
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    $\begingroup$ Given that there are easily tens of millions of 3 foot tall humanoids on earth have you done any research into the average height of 3 year olds? $\endgroup$
    – sphennings
    Sep 13 at 5:37
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    $\begingroup$ Sure, but you've got order of magnitude. Multiply by something between 0.4 and 2.5 to suit your class of hunanoid. BMI is a bad idea for non adults, IIRC, unless there's a children's curve. Try asking how much mess a 4 year old humanoid can make! $\endgroup$ Sep 13 at 6:25
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    – Zeiss Ikon
    Sep 13 at 11:44
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    $\begingroup$ LADIES AND GENTLEMEN: When you see as the first comment to any post a complaint by the Community Bot - you shouldn't be answering the question either below or in comments (which you should never do anyway). When the question is so ambiguous or lacks so much detail that the Bot gets involved, you should set aside your belief that you can assume/guess/telepathically-figure-out what the OP is talking about and instead post comments helping the OP write a better question. $\endgroup$
    – JBH
    Sep 13 at 15:39

3 Answers 3


Assuming the same proportions as a "normal" human (bad assumption, see below), weight is proportional to volume, hence to the cube of height -- that is, a creature with double the linear dimension (height) would weigh 2^3 = 8 times as much, so your three foot dwarf would weigh about one eighth what a six foot human would.

However, notice the size of a mouse's legs relative to its body, vs. the size of an elephant's. Strength of limbs scales only as the square of height (it's based on cross sectional area rather than volume), so the larger the creature, the relatively thicker its limbs need to be in comparison to its height.

There are three ways a race evolved (or created) to be half as tall might deal with this: they might weigh more, by carrying additional muscle, making them stronger relative to their size and weight than the prototypical 6 foot human (or by running strongly to fat, perhaps as a store against famine or hibernation); they might have skinnier legs (and likely arms) relative to their height, breaking their proportions and making them more similar to a monkey or small ape in terms of body appearance; or (if created rather than evolved) they might maintain human proportions and simply have stronger legs relative to the rest of their body (the difference likely wouldn't make them incredible jumpers, but they might do well at power lifting).


Here is Commodore Nutt


commodore nutt

He was an American entertainer and showman and a contemporary of General Tom Thumb.
Nutt was 29 inches tall and 25 pounds. General Tom Thumb was 40 inches (1 metre) and 70 pounds (32 kg).

I was a little skeptical of the 25 pounds for Commodore Nutt. But Google gave me this

nutt weight

from The Normal Higher Arithmetic an 1877 math textbook. Dang, Google!

So there is a fair range of weights for humans around your desired height.


Suppose they are similar to humans living in an earth-like environment.

BMI = mass (kg)/ height2 (m) = 703 × mass (lbs)/ height2 (in)

As told here:

Healthy BMI range is 18.5 kg/m2 - 25 kg/m2.

Therefore, healthy range of weight for a 3 feet tall person is 34.1 lbs - 46.1 lbs.

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    $\begingroup$ BMI is used for convenience but doesn't scale well outside the average adult range. Corpulence Index is better (but still not perfect) for small people, and gives a range of roughly 17.5 - 21.5 lb for 3 foot adult. $\endgroup$ Sep 13 at 14:17

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