Updated October 24, 2020 by Daniel Imperiale

The 10 Best Atomic Watches

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This wiki has been updated 14 times since it was first published in February of 2018. Atomic clocks are considered to be the most accurate timekeeping devices that human beings have devised to date, and if you want the timepiece on your wrist to match one, you're going to want to get your hands on one of these watches. They receive radio updates from sources around the world, and we've ranked them by style, functionality, and the reliability of their connection to a signal. When users buy our independently chosen editorial choices, we may earn commissions to help fund the Wiki. If you'd like to contribute your own research to the Wiki, please get started by reviewing this introductory video.

1. Seiko Coutura SSG021

2. Casio G-Shock GX Series

3. Junghans Max Bill Mega

Editor's Notes

October 23, 2020:

While a lot of the models on our previous list have remained, we saw fit to update a few prominent selections to reflect their company's current lineups, like the Seiko Coutura SSG021, a black PVD-coated model that offers a nice chronograph function with a bright blue ring around its 60-minute subdial that makes it particularly legible. We also updated one of our more budget friendly models to the CoolFire Solar 1531, which features a more durable band and a classier dial design than its predecessor.

Casio's G-Shock models continue to be among the best offerings for atomic timekeeping, and we added a new one in the Casio G-Shock MT-G, a model that bolsters its resin construction with stainless steel for added durability and to bring it line with some of the most popular steel sports models on the market. And new to our special honors section you'll find a high-end Seiko chronograph with GPS-based radio reception that eliminates the need to change your home city for it to seek a relevant local signal.

June 28, 2019:

While our previous example of this ranking was almost completely dominated by Citizen and Casio models, we wanted to diversify a little more this time around, and fortunately for us, models by Seiko and Junghans came along to save the day. The former is a capable pilot's chronograph with defined style and a rugged build. The latter doesn't look quite as robust, but is firmly rooted in its origins as a classic German timepiece associated with the renowned Bauhaus Art School. Those pieces are so fine that they came in at numbers one and three respectively. Our previous number one option left due to availability concerns, and our older number three, the Citizen Navihawk AT, slotted back to number four. We still love that watch, but between its quartet of subdials, dual digital displays, and slide rule bezel, it seems a little too busy.

Special Honors

Seiko Astron Chronograph This is one of the higher-end models from the company, with a stainless steel case that has a rose-gold coating and comes on a flexible rubber strap. Combined with 10-bar water-resistance and GPS-assistant radio signal seeking, it's an offering that you can strap on and not think about until you need to check the time. seikowatches.com

4. Casio G-Shock Solar Orange Unisex

5. Casio G-Shock MT-G

6. Citizen Eco-Drive Promaster Skyhawk

7. Citizen Eco-Drive World Perpetual

8. Casio Rangeman GW-9400-1CR

9. Casio Wave Ceptor

10. CoolFire Solar 1531

How An Atomic Watch Keeps Time

This doesn’t happen constantly, however, as non-stop communication with an atomic clock would put an unnecessary strain on the watch’s battery life.

While it might be fun to imagine a little atom of some particular material living inside each atomic watch and somehow being used as a timekeeping mechanism, that’s not exactly how these devices function. In fact, an atomic watch relies on various atomic clocks around the world to regulate it. This doesn’t happen constantly, however, as non-stop communication with an atomic clock would put an unnecessary strain on the watch’s battery life.

So, an atomic watch keeps time the same way that any quartz watch keeps time. It relies on the piezoelectric properties of quartz crystal, which cause it to respond to an electrical charge by vibrating 32,768 times per second. Those oscillations are then translated by a series of switches to create a pattern of one pulsation per second, and that pulsation moves the gears in the watch (or relays the change to a digital display).

An atomic watch doesn’t use its radio connection to keep time, then, so much as it does to set the time. With one of these models on your wrist, you never have to pull out a crown and spin the hands around or press a series of buttons to set the hour or the minute. The watch connects via 60 Hz radio signal to the time being constantly relayed from a local source, allowing it to set itself.

For owners in the United States, this means connecting with the atomic clock housed in Fort Collins, Colorado. Your watch will check in with the radio signal being broadcast from this location about once per day. Some watches check more often than that, but this really only comes in handy for frequent travelers who would want their timepiece to automatically adjust when it enters a new time zone. Quartz watches rarely lose more than a fraction of a second per day, making frequent check-ins redundant at home.

For those frequent travelers, it’s important to look for a watch that can communicate with atomic clocks from around the world. Most major countries or regions offer an atomic clock for their time zone, so you should never have to reset the watch while you’re traveling. Some brands offer better connectivity than others, though, so keep an eye out.

Additional Features To Look For In An Atomic Watch

Beyond the ability to check in with a given atomic timekeeper, an atomic watch stands to offer just about anything else you can want from a watch short of a mechanical movement — after all, these have to be quartz-powered devices to make any sense. Any feature you may prefer in your watches — from chronographs and alarms to tide graphs and GPS tracking — is available to you in an automatic watch. What exactly you want is a matter of personal preference, but knowing all you can about each feature can guide your hand.

These are great for athletes, but are also useful for anyone who needs to time regular activities.

And to the point of hands, in particular, you can decide whether you want an analog or digital face on your watch. Analog implies the old-school way of telling time, with a big hand counting minutes and a small hand counting hours. Some watches will even place a pair of analog hands on top of a digital face, giving you the best of both worlds. Be careful with these, however, as they can get a little busy, and the hands occasionally block your view of certain digital features.

In mechanical watch terms, a chronograph is a watch’s ability to function as a stopwatch, with a single pusher instigating a count-up timer that relays seconds and subseconds to the user. On digital watches, this display is even more accurate, as it will often count time as minuscule as hundredths of a second, offering built-in memory for split laps, to boot. These are great for athletes, but are also useful for anyone who needs to time regular activities.

Another common feature on atomic watches is an alarm, and this can be both a blessing and a curse. Users worried about being late for a meeting while traveling for work can rest assured that their watch will adjust itself to whatever time zone they’re in, and that it will go off reliably and accurately. Certain alarms and notification sounds — such as beeps at the top of the hour — can be a big problem in theaters, libraries, or somber settings where digital noises are unwelcome. If you utilize this feature, make sure it’s easy to turn on and off as you enter such spaces.

A Brief History Of Atomic Timekeeping

The atomic clock from which your new watch is going to procure its setting is a fascinating device that can trace its roots to the dog days of the late 19th century, when it was first suggested by Lord Kelvin (of Kelvin temperature scale fame). He wouldn’t live to see experiments in the field, however, as it took until the height of the atomic age for an American scientist named Isidor Isaac Rabi to develop the first experimental devices.

A deep enough investigation of the question will eventually cause your sense of time and, thus, reality, to unravel rather quickly.

These early experimental atomic clocks used an ammonia absorption line that proved less accurate than quartz clocks of the day (which were still 30 years from inciting a revolution in watchmaking). It wasn’t until 1955 that Louis Essen constructed an atomic clock based on the radiation from an atom of caesium-133.

That standard — 9,192,631,770 cycles of radiation emanating from a single atom of caesium-133 — has become the agreed-upon delineation of the duration of a single second, and atomic clocks around the world use it to determine the time (with a minor astronomical discrepancy you'll occasionally hear of called the leap-second). To a layman, this must seem awfully arbitrary. Why wouldn’t a second correspond to 9,192,631,771 cycles? A deep enough investigation of the question will eventually cause your sense of time and, thus, reality, to unravel rather quickly. It’s best to accept both the necessity of a society’s commitment to such a standard on one hand, and allow your brain to function without stressing over its irrelevance on the other.


Daniel Imperiale
Last updated on October 24, 2020 by Daniel Imperiale

Daniel Imperiale holds a bachelor’s degree in writing, and proudly fled his graduate program in poetry to pursue a quiet life at a remote Alaskan fishery. After returning to the contiguous states, he took up a position as an editor and photographer of the prestigious geek culture magazine “Unwinnable” before turning his attention to the field of health and wellness. In recent years, he has worked extensively in film and music production, making him something of a know-it-all when it comes to camera equipment, musical instruments, recording devices, and other audio-visual hardware. Daniel’s recent obsessions include horology (making him a pro when it comes to all things timekeeping) and Uranium mining and enrichment (which hasn’t proven useful just yet).


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