How to Read a Watch Spec Sheet

A spec sheet can look like a wall of numbers. Each one answers a practical question, and a few matter far more than the rest.

Case diameter is the figure everyone quotes, measured across the case without the crown. But it does not tell you how a watch sits on the wrist. Two watches of the same diameter can wear very differently.

Lug-to-lug length is the distance from the tip of the top lugs to the tip of the bottom ones. This is the number that tells you whether a watch will overhang a smaller wrist. If the lug-to-lug is longer than the flat top of your wrist, the watch will feel too big whatever the diameter says.

Thickness decides whether a watch slides under a cuff. Dress watches are often slim, while divers and chronographs are thicker. A few millimeters make a noticeable difference.

Lug width is the gap between the lugs, and it is the size of strap you can fit. It matters if you like to change straps, since many brands offer straps in standard sizes.

Water resistance is a laboratory rating, not a diving depth. See our guide to water resistance ratings for what each level means in daily wear. A screw-down crown is a sign of a more serious seal.

Power reserve tells you how long an automatic or manual watch will run after it is fully wound and then taken off. A few days is useful if you rotate watches, and shorter reserves are fine if you wear one every day.

Weight is easy to overlook, but a heavy watch on a bracelet feels very different from a light one on a strap. Titanium cases are noticeably lighter than steel.

Finally, look at the movement and caliber, the jewel count, and any antimagnetic rating if you work near laptops and speakers. Our watches page lets you filter by power reserve, weight, and size, and the compare page shows the numbers side by side.