Let's talk about necklace lengths and how to achieve them:
Most necklaces are about 16'. This length is good because it will most likely allow your pendant to show above your collar. A longer one is 18", and these might need to be worn over the shirt to be seen.
Any necklace longer than 20" usually seems "long." If your necklace, dangles, or pendant hang below bust level on the wearer, they can hit a table when the wearer is seated, so just be aware of that.
Any necklace shorter than 15" can begin to be a "choker" on some people. We all have different sizes of necks, which is why it's always nice to make necklaces be adjustable length with an extender chain.
How to go about getting the length you want: You have to include all the findings you want in the total length. You can actually measure the clasp and all the jump rings you want to use and add up the length to see how much it will add to the entire necklace. Then, make sure to subtract that amount from the beads on your necklace to attain the desired length.
I hope you've enjoyed this journey through necklace creation as much as I have!
See you next time!
--Pam