Watch sizing: the numbers that predict fit

Diameter is the least useful measurement on the spec sheet.

Lug-to-lug decides everything

Measure the flat part of your wrist and keep lug-to-lug inside it. A 40 mm case with 50 mm lug-to-lug overhangs where a 42 mm case with 47 mm sits comfortably.

Thickness decides wearability

Under 10 mm slips under a cuff, 12 mm and up will catch. Case-back curvature matters too: a domed back sits into the wrist and wears thinner than the number suggests.

Lug width and strap options

Standard even widths give you the widest strap choice. Odd or integrated lug widths lock you into specific straps, often at manufacture prices.

Bracelet versus strap

A bracelet adds perceived size and weight; a leather strap makes the same case wear smaller. If you are between sizes, try the smaller case on a bracelet rather than the larger case on leather.

How Chrono24 Watches applies this

Every watch we list is opened and inspected before it appears on the site. We verify the calibre against the reference, examine dial printing and lume ageing under magnification, record timing across multiple positions on a calibrated timegrapher, measure bracelet stretch, and pressure-test sports references with intact cases. What we find is published on the listing, including the flaws, and photographed. You can read the full process on our authentication page.

Buying with confidence

Shipping is free, fully insured and requires a signature on delivery. You have fourteen days from delivery to return any watch for a full refund, for any reason, using a prepaid insured label, and every mechanical watch carries a twelve-month warranty on the movement. Our authenticity guarantee has no expiry date. If this is your first purchase from us, start with how to buy.

Next steps

Start with the full catalogue, read our authentication process, or email sales@chrono24watches.st with any question about a specific listing.