need help calculate quantities

[Daisys and Diamonds]

so im making a twisted pearl necklace -possibly called a Torsades necklace ???
inspired by this

i have loved this look for a long time
i dont think it looks like a healthy arrangment for the pearls so perfect for some pretties from Ms Wen

AA 7.3-8.3mm misc color near round potato freshwater Pearl​

im only using the ones without the grey tones
im pretty happy with the colours, there are not many the wrong colour
anyway anyway
im thinking two stand and about a finished length of 19- 20 inches
as much as i would love to rock a chocker (the '80's coming out in me) i now have old lady fat neck -i dont know how the old Queen Mary did it ?
as the strands are twisted i will need more pearls than just for a regular knotted necklace

can someone help me out
please
and
thank you

my pearls look a little bigger than Di's and i want the twists quite tight

 

[molinePDG]

Remember the more you twist the more length you're going to need. Based upon no evidence and just guessing, I would want at least 22 inches per strand before the twist, and maybe even more depending on how much you are planning on twisting it and if you are going to put any knots in between them

This afternoon I am happy to grab a couple of strands and do some testing for you

 

[Daisys and Diamonds]

Remember the more you twist the more length you're going to need. Based upon no evidence and just guessing, I would want at least 22 inches per strand before the twist, and maybe even more depending on how much you are planning on twisting it and if you are going to put any knots in between them

This afternoon I am happy to grab a couple of strands and do some testing for you

thank you Andrew, that is very kind

 

[molinePDG]

So a couple of things:

If you are doing one half twist at the end of the strand, it doesn't really change overall length as measured flat (it's just twisted end over end), which makes sense

Where it does effectively lower length, though, is by the now-changed width of the pearls. For example, twisting two strands of 7mm together really means that, effectively, it's behaving like 12-14mm pearls in some places because of how it will sit against your neck.

This does change the effective overall length, not taking into account knots.

I am happy to post pictures if you need anything, but I would say still standing by my original guesstimate of starting with something 22 inches or so, twisting, seeing how you think it fits (and taking potential knots into consideration). If you're using pearls around the 7-8mm size, I think anything beyond three strands twisted starts to get a little unwieldy to wear and finding clasps etc, but this is of course entirely personal preference.

 

[Daisys and Diamonds]

So a couple of things:

If you are doing one half twist at the end of the strand, it doesn't really change overall length as measured flat (it's just twisted end over end), which makes sense

Where it does effectively lower length, though, is by the now-changed width of the pearls. For example, twisting two strands of 7mm together really means that, effectively, it's behaving like 12-14mm pearls in some places because of how it will sit against your neck.

This does change the effective overall length, not taking into account knots.

I am happy to post pictures if you need anything, but I would say still standing by my original guesstimate of starting with something 22 inches or so, twisting, seeing how you think it fits (and taking potential knots into consideration). If you're using pearls around the 7-8mm size, I think anything beyond three strands twisted starts to get a little unwieldy to wear and finding clasps etc, but this is of course entirely personal preference.

thank you so much Andrew
that helps a lot