Necklace length reference
This is a general reference for a necklace length.
Of course, this is just an average.
All lengths depend on your own body type and size.
Someone who is 6 foot 3 will not have the same results with necklace length as someone who is 4 foot 8.
Although, that should be obvious, it still needs to be said.
Also remember that some people should take bust size into account. :)