Watch water resistance: the women's versus men's gap

The finding

We recorded the water resistance rating declared by the manufacturers on the watches in stock, then cross-referenced it with gender. The two populations are of comparable size, which makes the comparison direct.

How to read this: out of 1,860 women's watches, 715 are limited to 3 ATM, which is 38.4%. Scope: watches active and in stock on 5 August 2026 with a declared water resistance.

The mechanism: it all comes down to diameter

The water resistance of a case depends on the volume available to house the seals and on the screw-down surface of the case back. The less room there is, the more constrained the construction. Sorting the same watches by diameter band, with no distinction of gender, the gradient is clear.

The median diameter recorded is 36 mm for women's watches and 44 mm for men's watches, over 3,953 references with the field filled in. The water resistance gap between the two ranges therefore follows from a choice of format, not from a decision aimed at women.

What each rating really covers

The rating engraved on the case back comes from a static pressure test (standard ISO 22810). It does not describe a swimming depth: an arm movement in water generates far higher pressure peaks. This is the most frequent source of misunderstanding.

In practice: 3 ATM covers rain and splashes, nothing more. 5 ATM tolerates the occasional shower. You need 10 ATM to swim at the surface without thinking about it. Within our scope, only 17.2% of watches reach that threshold.

A limit that ages

One point the ratings never mention: water resistance rests on elastomer seals that harden with time, heat and toiletries. A watch that has not been serviced for several years no longer holds its original rating, whatever the figure engraved on it. The figures in this study therefore describe the as-new condition, not the condition after five years of wear.

Methodology

The scope covers watches active and physically in stock on 5 August 2026, with a water resistance declared by the manufacturer: 3,874 references, of which 3,953 have a recorded diameter. The ratings are those communicated by the brands, with no retesting on our part.

This scope is that of the accessible market: widely distributed fashion watches and entry to mid range models. It covers neither high horology nor professional diving watches, where the split would obviously be different. The shares are calculated on references in stock, not weighted by sales volumes.

The figures can be regenerated identically from the datasets below.

Datasets

Published under Licence Ouverte 2.0 (Etalab), compatible with CC BY 4.0. Free to reuse, including commercially, provided you cite the source and give a link to this page.

A question about the method, or need an extract on a particular segment? Our editorial partnerships page sets out what we can provide. The other editions are gathered on the Observatory page.