Fit and Sizing

Fit is the quiet thing that decides whether a piece is worn or left in a drawer. A diamond can be perfect and the piece still wrong if it sits too tight, hangs too long, or spins on the finger. Here is how to get each right.

Rings Ring size is the measurement that matters most and the one most often guessed wrong. Fingers change through the day and the year: they swell in heat and after salt or exercise, and shrink in cold, so measure at a neutral time, not at the extremes. A ring should pass over the knuckle with a little resistance and sit without spinning. A comfort fit, with a gently rounded inner edge, wears more easily, especially on wider bands.

One decision cannot easily be undone: a full eternity band, set with stones all the way round, usually cannot be resized, because there is no plain metal to cut and rejoin. If your size is not settled, choose a half-eternity, which can be sized. For any ring you are unsure of, getting measured properly by a jeweller is worth the trip.

Necklaces and chains Length decides how a necklace sits and reads. As a rough guide: around 16 inches sits at the base of the neck; 18 inches, the most common and versatile, rests at or just below the collarbone; 20 to 24 inches sits lower on the chest and layers well over shorter chains. Necklines matter too, since a fine chain vanishes under a high collar where a slightly heavier one holds. An adjustable chain is the simplest answer to all of this, letting one piece work at several lengths and layer at different heights.

Bracelets A bracelet should sit close but move freely, with room to slide a fingertip beneath it. Too tight and it cannot drape, which is half the look of a line bracelet; too loose and it spins or rides over the hand. Measure the wrist and add a small amount for comfort. Unlike a ring, a bracelet is harder to adjust well after the fact, particularly a tennis bracelet, where length is set by the number of stones, so getting the measurement right at the start matters.

Earrings Earrings are the one piece without a size in the usual sense, but fit still shows in weight and security: a heavier earring drags on the lobe over a day, and the back or closure decides whether it stays put. For studs of any size, a secure back; for hoops, a closure that clicks firmly shut.

How to think about it Measure rather than guess, allow for how the body changes through the day, and choose adjustable lengths where you can, since they forgive a great deal. And before buying any full eternity ring, be sure of your size, because it is the one fit decision that is difficult and costly to change later.