Chains: Length: 16", 18", 20" Sterling Silver - Flat Cable - 1.3 mm 14k Gold Filled - Flat Cable - 1.4 mm or 1.5 mm (20") The easiest way to find out how a necklace length will fit you is to measure necklaces you already have. If you don’t have a necklace with a similar length to what you are looking to find, you could use a string, cord, etc. and wrap the string around your neck. Be sure to have the string pressed against the nape of your neck and adjust one end so that the string falls the way you want your necklace to look, then mark where it meets back with the string. Use a tape measure or ruler to measure the string to find the ideal length. See a visual guide to the classic sizing for necklace lengths in our photo gallery.