1/8 or 17cm doll (what age?)

1-2 year old normally.

 

I think it depends on the doll and its proportions and also whether you prefer to think inside the box or outside of it.

Yes some are maybe designed to represent a young child but others aren’t as clear.
Those with more fantasy or exaggerated aspects could be any age really. Small doesn’t always mean baby or child, from a factual point of view there are conditions such as dwarfism for example, then there’s also various otherworldly beings of lore such as the fae folk who come in many shapes and sizes or what about fictional races such as Tolkien’s Hobbits?!
It’s down to the imagination of the individual and how they perceive distinctions of age and size.

 

A doll that is 17cm tall and in scale 1/8 would represent a full scale person who is 136cm tall. So an older child, perhaps around 10 years old, or so.
But that assumes a realistically proportioned doll.

If the doll is proportioned as a smaller child, the scale given is probably off. If the doll is proportioned to represent a two year old at 17cm, that would make it closer to 1/5 scale.

You can look up charts for average height for different ages online and then you just do the math.

But, as Blodeuwedd points out, it depends a lot of what you are going for style wise. Very often dolls have exaggerated proportions with enlarged heads, and very small hands and feet. Sometimes they are made to be cartoon-ish and you can apply almost any age you like to them.
Very often, the context you place the doll in is what will determine how you read the doll. The scale of furniture and props is a big one, especially common place things that usually have a standard size in real life. The size and look of other dolls is another big one. If you place a Narsha next to a JID, she reads as an older child or pre-teen. If you place her next to a 55cm doll with a similar head size, she reads as a toddler.

 

On the left the body height is 19cm, and on the right is 22cm，I think age can be different.

 

Yes, it sort of depends as well if you want them to be in scale with an SD doll as an adult, or an MSD doll as an adult. I've seen a 1/8 Myou doll put with an MSD Sartoriaj doll to be toddler sized.

 

Aww no, that’s such a shame.
I think 1/8 size will be too small for a 60cm @dbfalcao, if you look in the msd sized discussion section and in the Iplehouse fid and SartoriaJ threads you will find posts where some 1/8 size have been used as toddlers for fashion bjd. May need to go bigger.

 

I checked from an artist anatomy book, and a 3 year old should be approximately half the size of an adult. (Adult male 180 cm, a 3 year old about 90 cm). So for a 60 cm adult, a small child should be somewhere around 25 cm. Maybe a Fairyland LittleFee would be close to the right size. Some of the faces are quite young looking (Ante, Bijou), and the bodies are rather chubby. It's hard to tell without seeing the dolls together because the sizes of the heads make a big difference in how the proportions look.

I found a comparison picture of Fairyland dolls. The third from the left is a LittleFee, the rightmost one is a Feeple60cm. To me the LittleFee would be in good proportion to a 60 cm doll. A 16 cm one would be the right size for a MiniFee sized adult.
All Sizes!

 

It really depends on the scale you're working with and the size of the adults, plus also the "real" height of the adults--like would you consider your 60cm adult doll's character to be 5'5" or 6'5" if they were real? And then it's just a bunch of math conversions, if you want it to be perfectly realistic. For example:

60cm doll in your character's world would be 180cm if they were real.
You want a 2 year old child. Average height of a two year old girl is about 85cm.

180 divided by 85 is about 2.12. So your adult should be about 2.12 times the size of your child. Which means next to a 60cm adult doll, a two year old child doll should be about 28cm.

OR

You just say "who cares?" about realistic proportions because BJDs aren't realistically proportioned and finding a child doll in the exact right scale is nearly impossible, so go with whatever is aesthetically pleasing to you.