Water Resistance Ratings on Wearables and Earbuds, Explained
Two different rating systems appear on wearables and earbuds, and they are routinely treated as interchangeable in listings. They test different things, and the difference decides whether you can swim in a device.
IP ratings: dust and splashes
An IP rating has two digits. The first is solid ingress — dust. The second is water.
| Rating | Water protection | Practical meaning |
|---|---|---|
| IPX4 | Splashes from any direction | Sweat and light rain. The common minimum for workout earbuds. |
| IPX5 | Low-pressure jets | Heavy rain, rinsing under a tap |
| IPX7 | Immersion to 1m for 30 minutes | Survives being dropped in a sink or puddle |
| IPX8 | Immersion beyond 1m, depth stated by maker | Depends entirely on what the maker specifies |
| IP68 | Dust-tight plus IPX8 immersion | Good general protection, but see the caveat below |
An X means that aspect was not tested — IPX7 has no dust rating at all. That is not necessarily a problem, but it is not the same as passing.
ATM ratings: pressure, and therefore swimming
ATM comes from watchmaking and refers to static pressure, expressed as an equivalent depth. The crucial and widely misunderstood point: these are static-pressure figures, not swimming depths. Moving your arm through water raises the momentary pressure far above the static value.
| Rating | Safe for | Not safe for |
|---|---|---|
| 3ATM | Rain, handwashing, sweat | Showering, swimming |
| 5ATM | Swimming in a pool, showering | Diving, high-speed water sports |
| 10ATM | Swimming, snorkelling | Scuba diving |
If you want to swim with it, look for 5ATM
IP68 alone does not authorise swimming. IP tests use still, fresh water at a fixed depth for a fixed time — nothing about that resembles a swimming stroke. A device rated for swimming will say 5ATM, or state swimming explicitly.
What no rating covers
These exclusions apply to essentially every consumer device, at any rating:
- Hot water and steam. Heat expands trapped air and softens seals; steam molecules pass where liquid water would not. Showers, hot tubs and saunas are outside every rating. This is the single most common way people flood a "waterproof" watch.
- Salt water. Not because it gets in more easily, but because salt crystallises in the seals and corrodes contacts. Rinse with fresh water afterwards.
- Chlorinated pool water, over time, degrades seals and adhesives. Rinse after swimming.
- Soap, shampoo and sunscreen. Surfactants reduce water's surface tension, letting it through gaps it would otherwise bridge.
- High-speed impact. Jet-skiing, water slides, diving in. Impact pressure is far beyond static ratings.
Ratings age
Water resistance is not a permanent property. Seals are rubber or adhesive and they harden, compress and crack. Drops misalign the case. Charging ports collect grit that stops a gasket seating.
A three-year-old 5ATM watch is not a 5ATM watch any more, and no manufacturer warranty treats water damage as a defect. Assume protection degrades and stop swimming with an ageing device before it teaches you the lesson.
For earbuds specifically
Sweat is the real threat, not rain — it is salty and slightly acidic, and it pools in the exact recesses where the electronics sit. IPX4 is the practical minimum for exercise; IPX5 or above is better. Wipe them dry after a workout rather than putting them straight into a sealed case, where the moisture has nowhere to go.
Note also that many earbud listings rate the earbuds only and not the charging case. A wet case can destroy dry earbuds.