5ATM vs IP68 Waterproof Smart Watch Ratings Explained

Scroll through any smart watch or smart ring product page and you'll almost certainly spot a string of letters and numbers like "5ATM" or "IP68" sitting quietly in the specifications. Most shoppers skim straight past them, but these little codes actually tell you a great deal about how your device will cope with rain, sweat, washing up, and the occasional dunk in the pool. So what's the real difference in the 5ATM vs IP68 waterproof smart watch debate, and does it actually matter which one your device has? Let's break both standards down properly, in plain English, so you know exactly what protection you're getting before you buy.

Why Waterproofing Ratings Exist in the First Place

Wearable technology sits in an unusual position: it needs to survive constant contact with moisture — sweat during a workout, splashes while washing your hands, rain on a commute — while still housing sensitive electronics, a battery, and often a touchscreen. Manufacturers can't just say "it's waterproof" and leave it there, because "waterproof" means wildly different things depending on the conditions. Is it fine in a light drizzle? Can it survive a shower? Would it cope with a swim?

To avoid ambiguity, the electronics industry relies on standardised testing systems that measure resistance to water (and often dust) under specific, repeatable laboratory conditions. Two of the most common systems you'll see on smart watches and smart rings are ATM ratings and IP ratings. They're not competing systems exactly — they measure slightly different things — but comparing them side by side helps make sense of what you're actually buying.

What Does ATM Actually Mean?

ATM stands for "atmosphere," a unit of pressure. One ATM is roughly equal to the pressure exerted by the Earth's atmosphere at sea level, which is used as a baseline for describing how much additional water pressure a device can withstand.

A 5ATM rating means the device has been tested to withstand pressure equivalent to being submerged in water to a depth of roughly 50 metres in laboratory conditions. Crucially, this is a static, controlled test — it doesn't perfectly replicate a jump into a pool with added splashing, moving water, or thermal shock from suddenly changing water temperature. In practical terms, a 5ATM-rated device is well suited to swimming, showering, and being caught in heavy rain, though manufacturers generally advise against high-impact water sports like diving or water skiing, since the sudden forces involved go beyond the conditions tested.

Other common ATM ratings you might come across include:

3ATM: Suitable for splashes, light rain, and hand-washing, but not recommended for swimming or submersion.
5ATM: Suitable for swimming, showering, and everyday water exposure.
10ATM: Aimed at more serious swimmers and water sports enthusiasts, tested to withstand pressure equivalent to roughly 100 metres.

What Does IP68 Actually Mean?

IP stands for "Ingress Protection," and it's an international standard (IEC 60529) that rates how well a device's casing resists solid objects (like dust) and liquids getting inside. Unlike ATM, which is purely about water pressure, an IP rating always comes as two digits, and each digit tells you something different.

The first digit describes protection against solid particles, on a scale from 0 (no protection) to 6 (completely dust-tight). The second digit describes protection against liquid ingress, on a scale from 0 (no protection) to 9K (protection against high-pressure, high-temperature jets).

So when you see IP68, here's what each number means:

6: The device is fully dust-tight — no dust can enter the casing at all, which matters for the fine internal components in a heart rate sensor or a charging port.
8: The device can be continuously submerged in water beyond one metre depth, for a duration and depth specified by the manufacturer (this detail varies, since "8" itself doesn't specify an exact depth — manufacturers state their own tested limit, such as 1.5 metres for 30 minutes).

This is the key nuance that catches people out: two products can both be labelled IP68, but if one manufacturer tested it to 1 metre for 30 minutes and another tested it to 2 metres for an hour, they've technically met different real-world benchmarks under the same headline rating. Always worth a quick check of the specific product page if you plan to push the limits.

So, Which Is "Better" — 5ATM or IP68?

Here's the honest answer: they're not directly comparable on a single scale, because they're testing different things. Think of it a bit like comparing a car's top speed to its fuel efficiency — both numbers tell you something useful about the vehicle, but neither one alone gives you the full picture.

ATM ratings focus purely on water pressure resistance and are historically borrowed from the traditional watchmaking industry, where they've been used for decades on analogue dive watches. IP ratings are a broader, dust-and-water standard used across all sorts of electronics, from smartphones to security cameras, not just wearables.

In practice, many smart watches and smart rings, including several models in the COLMI range, carry both types of rating simultaneously — for instance, an IP68 rating for dust and water resistance, combined with a 5ATM rating that specifically confirms suitability for swimming. When you see both, you're getting complementary information: the IP68 tells you dust can't get in and the device handles submersion, while the 5ATM confirms it's specifically been tested against the kind of sustained water pressure you'd encounter swimming laps or showering.

What These Ratings Do NOT Cover

This is arguably the most important section for avoiding an expensive mistake. Waterproof ratings, whether ATM or IP, are generally tested under specific, controlled conditions — and several everyday situations fall outside what's actually been tested:

Hot water: Showers with very hot water, saunas, and steam rooms can affect seals and gaskets differently than the cooler water used in standard testing.
Salt water and chlorinated water: Seawater and heavily chlorinated pool water can be more corrosive to seals and metal components over time than the fresh water used in laboratory tests. Most manufacturers recommend rinsing your device with fresh water after exposure to either.
High-impact water entry: Diving, jumping from a height into water, or water skiing create sudden pressure spikes that a static pressure test doesn't replicate.
Pressing buttons or touchscreens underwater: On some devices, operating buttons while submerged can force water past seals that would otherwise hold under passive submersion.
Ageing and wear: Seals and gaskets can degrade over time, especially if a device has been dropped or the strap and casing have separated slightly. A rating reflects the device's protection when new, not necessarily years down the line.

None of this means the ratings are meaningless — quite the opposite, they're a genuinely useful, standardised way to compare devices. It just means "waterproof" should always be read as "water resistant to a specific, tested degree," rather than an unconditional guarantee.

How Are These Ratings Actually Tested?

It's worth understanding roughly how manufacturers arrive at these numbers, because it explains why the ratings are trustworthy even though they can't cover every real-world scenario.

For ATM ratings, devices are placed in a pressure chamber that simulates the water pressure found at a specific depth — the chamber doesn't actually need real water, since it's testing pressure resistance rather than simulating a literal swim. The device is held at that pressure for a set period, then checked for any water ingress, seal failure, or damage to internal components once it's returned to normal atmospheric pressure.

For IP ratings, the testing process follows the IEC 60529 standard closely. Dust resistance (the first digit) is tested by placing the device in a sealed chamber filled with fine talc powder, sometimes with air circulated to keep particles suspended, for several hours, then checking whether any dust has penetrated the casing. Water resistance (the second digit) is tested differently depending on the exact rating being verified — for example, an IPX7 test involves submerging the device in water to a depth of 1 metre for 30 minutes, while higher water resistance figures may involve deeper submersion for longer durations, exactly as the manufacturer specifies for that particular claim.

Both testing regimes use fresh, room-temperature water and controlled, still conditions rather than the choppier, sometimes hotter, sometimes chlorinated or salty water you might actually encounter — which is precisely why the guidance about rinsing your device and avoiding extreme conditions exists. The rating tells you the device passed a specific, repeatable laboratory test; your job as the wearer is simply to keep your real-world use reasonably close to those tested conditions.

Practical Guidance for Everyday Use

If you're deciding how to treat your smart ring or smart watch day to day, here's a simple, sensible set of habits that respects most manufacturers' guidance:

Showering and hand-washing: Generally fine for devices rated 3ATM/IP67 or higher, though checking your specific model's guidance is always worth thirty seconds.
Swimming: Look specifically for a 5ATM rating (or higher) before swimming laps, and rinse the device with fresh water afterwards if you've been in a chlorinated pool or the sea.
Rain and general weather: Any IP-rated device with a second digit of 6 or above should comfortably handle rain and splashes.
Hot tubs, saunas, and very hot showers: Best avoided even on higher-rated devices, since heat affects seals differently to cold or lukewarm water.
Diving or water sports: Stick to devices explicitly marketed for these activities, since even a 5ATM rating isn't necessarily tested for the sudden pressure changes involved.

Waterproofing in COLMI Smart Rings and Watches

Because smart rings sit permanently on your finger — through washing up, showering, and swimming — waterproofing tends to matter even more for rings than watches, which people are more used to removing. The COLMI R10 Smart Ring is built with this in mind, carrying a robust water resistance rating that makes it genuinely practical to wear around the clock without constantly taking it on and off.

On the watch side, the COLMI P86 Smart Watch is a good example of a model designed for everyday water exposure, from rain to showers to swimming sessions, without needing to be removed for routine daily activities. As always, it's worth checking the specific rating listed on each product page, since exact depth and duration figures can vary slightly between models even within the same range.

Conclusion

The 5ATM vs IP68 waterproof smart watch question doesn't really have a single winner — both are legitimate, standardised ways of describing water and dust resistance, and many good-quality devices, including several in the COLMI range, carry both ratings together for a fuller picture. What matters most is matching the rating to your actual lifestyle: if you're swimming regularly, prioritise a confirmed 5ATM rating; if you mainly need protection from rain, sweat, and hand-washing, an IP67 or IP68 rating alone will usually serve you well.

Ready to find a ring or watch that can keep up with your routine, wet weather and all? Browse the full COLMI smart ring collection and smart watch collection to compare water resistance ratings alongside the rest of the specs, and pick the one that matches how you actually live.

Frequently Asked Questions

Can I shower with my COLMI smart ring or watch on?
Devices with a 3ATM/IP67 rating or higher are generally designed to handle showering, though very hot water and steam are best avoided, and it's always worth checking the specific rating on your product's page.

Is 5ATM enough for swimming?
Yes, 5ATM is the widely recognised threshold for casual swimming, including swimming laps in a pool. For serious open-water swimming or diving, look for higher ratings such as 10ATM, or a device explicitly designed for those activities.

What's the difference between IP67 and IP68?
Both ratings indicate the device is fully dust-tight (the "6"). The final digit differs: "7" typically means protection against temporary immersion up to 1 metre for around 30 minutes, while "8" indicates protection at depths and durations beyond that, as specified by the manufacturer.

Does a waterproof rating protect against sweat during workouts?
Yes — sweat resistance is one of the most common everyday uses for these ratings, and any device rated 3ATM/IP67 or above should easily cope with sweat from regular exercise.

Do waterproof ratings ever expire or wear out?
The rating itself doesn't expire, but the physical seals and gaskets that provide the protection can degrade over time, particularly after drops, knocks, or general ageing. Treating your device gently and avoiding unnecessary exposure to hot water or harsh chemicals helps it maintain its protection for longer.