Why thickness and lug-to-lug matter as much as diameter

Fit depends on more than the front view. Lug span, case curvature, back shape and centre of mass influence pressure, movement and sleeve clearance.

Find the effective span

Lug-to-lug generally describes the case span along the strap direction, but measurement conventions vary. Fixed projecting end links can extend the effective fit beyond the bare lugs. Find the first point that can genuinely bend down around the wrist.

Thickness has a shape

Crystal, bezel, middle case and back contribute to the height. Their proportions, a projecting back, inward-tapered sides and curved lugs can make equal measurements feel different. One height number cannot describe all wrist contact.

Balance and tension interact

A tall or heavy head can move on an overly loose strap, while overtightening causes pressure. Rotate the wrist, bend the hand and simulate typing or dressing. Stable, unrestricted fit can matter more than a small dimensional difference.

Common misunderstandings

Published measurements may differ because of tools or whether the crystal is included. Preserve an uncertain measurement as stated and use photographs or consistent measurement methods, rather than assuming every small difference proves a version error.

Your practical checklist

• Include fixed end-link projection in fit assessment.
• Observe how height is distributed.
• Try ordinary movements such as typing and using sleeves.