Measured: Judged by where the fabric edge crosses the throat, collarbone and shoulder, since each step lower or wider trades coverage for openness.
The basics
What to know about neckline
The neckline frames your face, so it is the first thing a viewer resolves and the detail that sets how formal the whole upper half looks. It also answers the practical questions before style enters. Those include which bra the garment allows and whether a necklace or earrings lead. They also cover how a jacket sits over it and how much shoulder meets the sun.
Judging follows the edge. Convention reads a neckline by where its line crosses the base of the throat, the collarbone, the shoulder point or below it. What that crossing exposes counts too. Each step lower or wider trades warmth and modesty for openness, and each changes the geometry. Vertical openings lengthen the neck while horizontal ones widen the shoulder line.
Treat the options as directions. Crew and turtleneck close upward, V and sweetheart open downward, and halter, one-shoulder, off-the-shoulder and strapless open outward across the shoulders. Pick the direction that balances your frame first. Jewelry follows by an old inverse rule: high necklines take long chains, and open ones take short pieces that sit on skin.