Princess

Princess covers 17 to 19 inches, 43 to 48 centimeters. 18 inches is the number a chain defaults to when a listing does not specify. The chain lands on or just below the collarbone, in the open triangle most necklines leave bare. That puts the low point of the necklace on skin rather than on cloth.

Pendants are engineered around this drop. The bail, the loop a pendant hangs from, is sized so the piece lies flat at roughly this length. At that drop, the weight hangs far enough from the throat to fall straight instead of riding up under the chin. That is also why 18 inches is the safe gift: it clears crew necks, scoop necks and open collars without adjusting anything.

Neck size shifts the result. On a neck measuring more than 16 inches an 18 inch chain climbs toward choker position, so 20 inches becomes the real princess equivalent. The weakness is competition. Worn under a shirt collar or a high neckline, the pendant lands on fabric and loses the contrast that makes it read. It also often sits at exactly the height of the neckline seam, where it snags.

String gives you the cheapest fitting there is. Cut a piece to 18 inches, hang it round your neck, and mark where it stops against the neckline you wear most often. Held next to a matinee chain, princess trades reach for stability. Less swing means less strain on the bail. A 5 gram pendant that would work a matinee clasp loose sits quietly at this length. Chain gauge deserves a look as well, since anything under about 0.8 millimeters kinks under a heavy pendant. A kinked link is where the chain parts.