What size watch should I wear?

Lug-to-lug is the measurement that matters

Lug-to-lug is the distance from the tip of the top lugs to the tip of the bottom lugs — the full length of the case. It decides whether the watch sits flat on your wrist or hangs over the edges.

A 40mm case with long straight lugs can wear larger than a 44mm case with short curved ones. If the lug-to-lug is wider than the flat of your wrist, the lugs lift the case and the strap angles awkwardly. It is the most common sizing mistake there is, and the diameter will not warn you about it.

Measuring your wrist

Wrap a soft tape measure around your wrist just below the wrist bone, where the watch will actually sit. Snug, not tight. No tape measure? Wrap a strip of paper, mark it, and measure the strip against a ruler.

Thickness decides whether it fits under a cuff

A dress watch is typically 7 to 10mm thick and slides under a shirt cuff without catching. Dive watches commonly run 13 to 16mm, and above about 12mm you will notice it snagging.

Thickness also changes how large a watch looks. A thick 40mm watch reads bigger than a slim 42mm one, because the case sits proudly rather than hugging the wrist.

Where the rules stop applying

These are starting points, not prescriptions. Deliberate oversizing is a legitimate style — plenty of people wear a 44mm watch on a 16cm wrist and it looks intentional rather than wrong. Vintage-styled pieces run deliberately small for the same reason.