If you want to make sure that you have the right length for your Puka Shell Necklace and you do not have a tailor's cloth tape measure, you can use string. Tie a piece of string around the neck with the desired amount of hang to it. Then cut off the string and measure it's length. This will be the size you need. Or you can take your shirt collar size, and add 1" to 2", so your necklace will fit as a choker.