How long should a necklace chain be?

[BabCNesbitt]

Buying a necklace for myself online and it gives a choice of chain lengths: 16", 18", or 24". What's 'standard'? Does it depend on boob size? Was going to wear it to a wedding but don't have the dress to wear with it yet.

Thanks!

[Motherwithflaws]

My favourite one is 20" I think, it depends on the width of your neck and how high up your boobs are and size wise imo.
Try it with pieces of string first?

[BabCNesbitt]

Brilliant, hadn't thought of that!

[ShotgunNotDoingThePans]

That's a great idea. I think I go for 16 or 18 in, never the long ones as they'd settle between my boobs - not a good look!