Whether looking for a reliable or functional timepiece, a smartwatch is currently the best in the market, equipped with various features, from GPS navigation to internet access and communication. Another feature to consider when purchasing a smartwatch or any device is water resistance, especially for those with active lifestyles or into outdoor activities. This feature gives extra protection to your device when it rains or if you accidentally drop it in a pool of water. But the question is, what’s the difference between IP, WR, vs. ATM in a smartwatch?
If you’re new to this feature, you’re most likely wondering how water resistance works on smartwatches and what those ratings mean. First, water resistance indicates how much pressure a watch can endure while in the water at a certain depth. A watch is water resistant if it can maintain accuracy and does not leak under water. However, the water resistance rating of smartwatches varies per device. Therefore, knowing what IP, WR, and ATM mean is vital in picking a water-resistant smartwatch suited to your lifestyle.
IP ratings: What do the letters and numbers stand for?
Also known as the International Protection Rating, the Ingress Protection (IP) Rating is a method that indicates the effectiveness of the electrical enclosure in preventing external objects from entering a device. The IP ratings indicate the device’s resistance against water and solid matter. It’s composed of IP letters and two numbers (e.g. IP65). If the number after IP is high, it indicates higher protection against foreign bodies. In the IP rating, the first digit signifies the enclosure’s level of protection against ingress, preventing leakage or entry of foreign bodies.
The second digit denotes the enclosure’s level of protection from restricting exposure of internal components to different forms of moisture. Also, the IP rating may contain three numbers or another letter (e.g. IP666/IP68A). The third digit or letter at the end of the IP rating is an optional supplementary information/protection added to the standard product. An X may also be used as a replacement for a number if its specification is not yet rated.
For instance, a high-powered jet with an IPX6 means it’s water-tested. If water projects to the device in any direction, it won’t cause detrimental effects on the enclosure. Meanwhile, IP6X indicates total protection against exposure and that there’s no entry of dust. It means the device has only undergone a dust test, and its water resistance is not yet rated. In short, IP rating refers to an electronic device’s water and dust resistance.
IP Rating: Dust Resistance/Mechanical Protection
| 1st Numeral | Dust Resistance/Mechanical Protection |
| 0 | No protection |
| 1 | Protected against 50mm/larger solid objects |
| 2 | Protected against 12.5mm/larger solid objects |
| 3 | Protected against 2.5mm/larger solid objects |
| 4 | Protected against 1.0mm/larger solid objects |
| 5 | Dust protected (not totally dust-tight) |
| 6 | Dust-tight |
IP Rating: Water Resistance
| 2nd Numeral | Water Resistance |
| 0 | No protection |
| 1 | Protected against dripping water vertically descending directly onto the device |
| 2 | Protected against dripping water vertically descending onto the device (15-degree angle) |
| 3 | Protected against spraying water on either side of the device (up to 60 degree angle) |
| 4 | Protected against splashes from any direction |
| 5 | Protected against gently projected water in jets |
| 6 | Protected against projected water from high-powered jets |
| 7 | Protected against temporary immersion in water |
| 8 | Protected against submerging continuously in water for a long duration |
| 9 | Protected against projected water at high temperature and pressurem |
What’s with the Apple Watch’s WR50 and WR100 ratings?
If you own an Apple Watch or are planning to purchase one, you’ll notice it has different water resistance ratings. Since the brand doesn’t have an official IP rating, Apple Watches has the WR50 and WR100 ratings. Apple Watches with the WR50 rating denote a water resistance of up to 50 meters. These watches are suited for shallow water activities, such as swimming in a pool or ocean and bathing in the shower. However, avoid using this watch when doing high-velocity water activities, like waterskiing, scuba diving, or submerging too deep in the ocean.
While most Apple Watches from Series 2 to 9 have a WR50 rating, the WR100 water resistance rating is only accessible on the 1st and 2nd generation of Apple Watch Ultra. This rating indicates up to 100 meters water-resistant, making the Apple Watch Ultra ideal for extreme water sports, from swimming in the ocean or pool to wakeboarding and kitesurfing. Moreover, you can use it while bathing in a hot tub or shower and even scuba diving up to 40 meters deep. So, if you’re looking for the perfect diving accessory, the Apple Watch Ultra will deliver.
What does 5ATM water resistance mean?
The watch should be motionless or static to calculate its water resistance. It measures the pressure it can withstand, indicated in ATM (atmospheres). A watch with a 5ATM water resistance can tolerate up to 50 meters of pressure or equal to 164 ft submerged. But note that ATM refers to the measure of pressure and not depth. Thus, a watch with a 5ATM rating is not ideal for diving to 50 meters deep. Some even say that a 5ATM watch is the same thing as a 3ATM water resistance, which can only endure pressures to a depth of 30 meters.
That’s why the general recommendation for everyday life watch is 5ATM. These watches are ideal for non-sport activities as they only offer protection against steam, splashes, rain, accidental falls, or quick dips. Although you can use it for shallow water activities, it is not ideal for bathing, showering, or diving. Hence, you should not rely on a 5ATM watch if exposed to moisture or swimming for extended hours. Nonetheless, a 5ATM rating indicates the watch has good quality since higher ATM ratings mean better and more precise components.
What does 10ATM water resistance mean?
A watch with 10ATM water resistance can withstand pressures equal to a depth of 100 meters. These watches are sturdier than those with a 5ATM water-resistant rating. Most ATM watches are also built with a screwed-down case back or crown, ensuring enhanced water resistance performance. But remember, 100 meters does not refer to the depth you can dive with using a 10ATM watch. Instead, it denotes the pressure at 100 meters depth while the water surface is static. Usually, showering will take 20 liters of water per minute, and the pressure will not exceed 10ATM.
Thus, you can use a 10ATM water-resistant watch while taking a shower. On the contrary, it’s not ideal to shower with hot water while using any watch as it will damage the device’s rubber ring seals, resulting in water vapor. In addition, a 10ATM water-resistant watch is not ideal for diving. But you can use it when swimming since you’re arms will move constantly, and the surface water will not remain static. So, if 3ATM is daily life waterproof, a 10ATM water-resistant watch is suited for swimming.
What does 20ATM water resistance mean?
When your watch has a 20ATM water-resistant rating, it can withstand pressures equal to 200 meters deep. A 20ATM water resistant is also the minimum rating required and used by professional divers since it offers protection against extreme circumstances. It also has a screwed-down case back and crown to ensure better performance and prevent flooding. Compared to 10ATM watches, a 20ATM watch also has a thicker glass. Hence, it can withstand more pressure when submerged, boosting its water-resistant performance.
In addition, watches with over 10ATM water-resistant ratings are more expensive as they offer more functionality. With a 20ATM watch, you don’t have to worry about leakage when it’s raining, snowing, or showering. You can even do extreme recreational sports while wearing a 20ATM watch, from swimming, snorkeling, and diving to surfing, kayaking, and other high-speed water activities. Thus, if you’re usually into extreme water activities, a 20ATM water-resistant watch is a good accessory, giving you extra peace of mind knowing it won’t leak.
But remember that a 20ATM water resistant can only bear pressures equal to a depth of 200 meters. It does not mean you can dive 200 meters deep with your watch.
What does 30ATM water resistance mean?
For professional divers or those into deep diving, a watch with a 30-ATM water-resistant rating is the best choice. It can bear pressures equal to 300 meters, making it ideal for professional divers. A 30ATM water-resistant watch also has an outstanding waterproof feature, like impermeable construction and secured seals. Another feature most 30ATM water-resistant watches boast is helium drainage valves. When shifting from high pressure to usual conditions, the drainage valves allow extra helium to get out of the watch, so it is suited for deep-sea diving.
But if the watch doesn’t have drainage valves, the helium won’t be able to escape the case during decompression. Once the helium is trapped inside, the pressure will cause severe damage to your watch. As a result, the crystal will instantly break, causing leakage to your timepiece. Additionally, a 30ATM water-resistant watch offers more functionality since there are fewer rules to follow. Since this timepiece has a helium escape valve, you can wear this watch while doing extreme water sports, like scuba diving and freediving.
In a nutshell, 30ATM water-resistant watches offer more performance and are fully waterproof than those with lower ratings. Therefore, if you’re searching for the best diving accessory, you can never go wrong with 30ATM water-resistant watches.
What Are ‘Bars’ in Water Resistance?
If your watch says 10BAR, it’s the same as 10ATM water resistant. Back then and up to this day, ATM or physical atmosphere refers to the standard unit for pressure. But in 1978, they changed the unit ATM into BAR in Austria and Germany since they could not define its exact meaning. 1BAR is about 1ATM or the air pressure equivalent to a depth of 10 meters. 10BAR corresponds to 10ATM water resistance or the capacity of a watch to withstand pressure equal to a depth of 100 meters. Hence, bars also indicate how much pressure a watch can withstand underwater.
On the other hand, bars only refer to the measure of pressure and not the depth. So, if a 5ATM and 10ATM water-resistant watch is not ideal for diving or extreme water sports, the same goes for watches with 5BAR and 10BAR ratings.
What does ATM mean?
ATM or atmosphere is the standard unit for pressure, measured in meters. In the watch industry, ATM water resistance refers to how much pressure a watch can bear underwater. This unit is also applicable to most underwater devices. But how do you determine how many meters of water resistance a watch offers? For instance, your watch has a 10ATM water-resistant rating. Multiply ATM by 10 to determine its water resistance in meters. So, if it’s 10ATM multiplied by 10, you’ll get 100 meters of water resistance.
This method applies to all ATM ratings, which means 3ATM is equal to 30 meters, 5ATM is 50 meters, and so on. As stated earlier, 1 bar is equal to 1 ATM, which corresponds to a depth of 33 feet or 10 meters. Thus, at sea level, 10 meters or 1 ATM is the starting point of pressure.
What does WR mean?
If we’re talking about watches, WR stands for water-resistant. In a pressure-tested watch, WR suggests how meticulously sealed it is against water ingress. You can determine if the watch is fit for wet surroundings or submerged to a certain level of pressure or depth based on its WR rating. To put it simply, WR relates to the liquid as water. It does not indicate dampness or humidity. Nonetheless, the water resistance rating is not similar to a water-resistant watch since the latter is for a specific depth.
For instance, if your watch has a 30m (pressure) rating, you cannot submerge it in water or dive into the ocean to a depth of 30 meters. But if you want to submerge your watch underwater, the minimum rating required is 50m. Meanwhile, removing the back case of the watch would compromise its water resistance. Over time, its effectiveness will also lessen when the parts and seals wear out.
Water Resistant Rating (ATM/BAR/WR)
| Water Resistant Rating | Pressure | Suitability |
| 3ATM/3BAR/WR30M | 30M | Light splashes & rain |
| 5ATM/5BAR/WR50M | 50M | Light splashes, rain, swimming, & boating |
| 10ATM/10BAR/WR100M | 100M | Light splashes, rain, swimming, boating, bathing, & shallow diving |
| 20ATM/20BAR/WR200M | 200M | Light splashes, rain, swimming, boating, bathing, & shallow diving |
| 30ATM/30BAR/WR300M | 300M | Light splashes, rain, swimming, boating, bathing, shallow diving, deep sea diving, & professional diving |
Water Resistant vs Waterproof Watch
While these terms are often used interchangeably, water resistant and waterproof are two distinct words with different meanings. Let’s take, for example, a 10ATM water-resistant watch. It can bear pressure corresponding to a depth of 100 meters, meaning you can use this watch when showering or swimming. However, you cannot submerge a 10ATM watch to a depth of 100 meters. Doing so will cause damage to your watch, resulting in breakage of the glass and leakage. Therefore, you can only immerse a water-resistant watch at a certain depth or pressure.
It only offers protection at a certain level, making it difficult for water to enter your watch, but it’s penetrable. Concurrently, a waterproof watch sounds more appealing to users since it means water cannot enter the device, regardless of how long it’s underwater. It means water cannot penetrate the watch no matter how long or deep it’s submerged. But as of writing, there is no such thing as an impermeable or waterproof device. It will still leak or flood at a certain point since pressure will surely break the watch crystal. So, when the manufacturer says a product is waterproof, it means water-resistant.
What is water resistance for a dive watch?
According to the International Standard Organization (ISO), a dive watch must have at least a 100-meter water-resistant rating. That’s why most dive watches have a 100-meter (10ATM/10BAR) depth rating. However, the average water resistance required for dive watches is 300 meters (30ATM/30BAR). For serious divers, the safest watch is one with a 100ATM/100 BAR rating. You may also opt for watches with Divers written on them or have an ISO 6425 certification since it’s a certified diving watch.
These watches are ideal to use underwater without worrying and are actually water resistant. Nonetheless, the activity you can do underwater depends on the water resistance rating of your dive watch. For example, 100 meters of water resistance is ideal for swimming, surfing, and snorkeling, but not diving. Meanwhile, a watch with a water resistance of 200 meters is only for marine activities, surface water sports, and skin diving. It’s not ideal for scuba diving.
Executive Summary
Overall, there are many factors to consider when choosing a water-resistant smartwatch. Knowing the differences between IP, WR, vs. ATM can also help you make the right choice. From your lifestyle to the intended activity to use it for, these are just some things you should consider before purchasing a water-resistant watch. However, don’t just depend on the water-resistant ratings since its definition may vary based on the tests performed by the manufacturer. Instead, it’s best to follow the guidelines provided by the manufacturer when immersing the product.
If a product claims to be waterproof, it’s better not to submerge it unless it states the water-resistant rating. Also, remember that the water resistance performance of your watch may lessen over time. So, never abuse it, no matter how rugged your watch is, even if it can withstand immense depths. But if you can’t avoid being in the water, maybe due to your work or lifestyle, it’s best to bring your watch to a watchmaker and test it for water pressure or replace its gaskets if necessary.
