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How to Choose an Altimeter Watch

Altimeter watches range from the most basic timekeepers that measure altitude to fitness and health tracking GPS-behemoths.
Thursday December 6, 2018

Altimeter watches offer a range of functions and data-gathering technology that give you information about the landscape and environmental conditions around you. Hunters, fishers, climbing guides, mountaineers, hikers, pilots, and vertical athletes can all benefit from the altitude and location data that these products offer.

A traditional model has three primary functions; altimeter, barometer, and compass (sometimes referred to as an ABC watch). With these three readings combined, you can map weather trends and determine your location. There are many different types of altimeter watches out there, ranging from those with the most basic functions to those stacked with features. In this 'Buying Advice' article, we discuss different model types, how altimeters work, key functions, GPS capability, and watch accessories. Below is a list of questions to ask yourself before buying one. We walk you through the questions and the answers.

Hiking in the high country of the San Juan mountains! Setting a storm alert is helpful to determine if a storm will move in or not. An important tool in the mountains where lightning can be a real shocker.
Hiking in the high country of the San Juan mountains! Setting a storm alert is helpful to determine if a storm will move in or not. An important tool in the mountains where lightning can be a real shocker.

Is an altimeter watch right for me?


Any outdoor recreationist can benefit from using an altimeter watch, but do you need one? In addition to regular time-telling functions, an altimeter watch calculates your elevation and allows you to track weather patterns. If it also includes a GPS, you can determine your location and even navigate to specific coordinates. If you are the type of person that typically sticks to marked trails, then an altimeter watch can be a fun accessory with some practical applications (it might be able to save you from getting too wet). If you often adventure into the unknown wilds, it can be an invaluable, potentially lifesaving resource.

Before you begin your search, you need to ask yourself a few key questions:

1) What will you be using your watch for?
2) How long does your battery need to last?

3) What kind of features do you want?

Once you know the answers to these key questions, you can begin your search in earnest.

Climbers may find the total ascent and descent function helpful for training and data tracking, while hikers and mountaineers may use the altimeter function to determine the relative location of a camp in white-out conditions. Many explorers looking for the next first ascent of a big mountain can use an altimeter watch to determine summit information like the altitude of a peak or the elevation of new camps along the way. If you primarily need a quality timepiece, you may be better off checking out some basic models that don't come with the same lofty price tag as many altimeter watches. However, if you're in the market for something that can help you determine where you are, where you've been, and where you're going, an altimeter watch may be what you've been looking for.

Altimeter watch testing on Denali  we carried several altimeter watches to the 20 320ft summit of Denali for side by side in the field comparisons.
Altimeter watch testing on Denali, we carried several altimeter watches to the 20,320ft summit of Denali for side by side in the field comparisons.

Types of Altimeter Watches


There are two primary categories of altimeter watches. First is the traditional altimeter watch that comes with a basic complement of ABC features and are either solar powered or have a replaceable battery. The second type is the more powerful GPS watch. GPS models have rechargeable batteries and usually come with a whole lot of features that you don't get with a traditional altimeter watch. These watches can often do a lot, but their battery life also limits them. Check out the pros and cons of both types below to see which best suits your needs.

Traditional


A traditional ABC watch features an altimeter, barometer, and in most cases, a compass. They have simple watch batteries or a built-in solar panel.
  • Pros: More reliable, much longer battery power, lightweight, often inexpensive
  • Cons: Fewer features, don't tend to look as good, displays usually feel a little antiquated
  • Best Uses: Long adventures, tracking vertical gain/loss, timekeeping
  • Watch Examples: Casio PRW-6000Y, Casio PAG240B-2, Casio SGW300HB, Suunto Core Alu

All GPS contenders. From left to right: Suunto Ambit3 Peak  Garmin Fenix 3  Suunto Traverse.
All GPS contenders. From left to right: Suunto Ambit3 Peak, Garmin Fenix 3, Suunto Traverse.

GPS-based


A GPS-based watch can capture signals from satellites to determine your location. Based on the power of the watch, its capabilities vary quite a bit. GPS watches offer many fancy features in addition to the traditional features of an altimeter watch. Not only are they great for tracking vertical gain/loss, and weather trends, but they often also provide a fitness log, sometimes for a wide variety of activities.

They typically sync with a smartphone and connect to apps. With this integration, you can upload programs, games, and virtual pacers to help you with your fitness training. It also provides you with trip information (e.g., distance, pace, time), and you can navigate with some watches. The primary downsides are short battery life and a hefty price tag.
  • Pros: Lots of features, navigational capabilities, can replace a handheld GPS, user-friendly interfaces
  • Cons: Short battery life in GPS mode (~8 to 50 hours, based on power settings), expensive, sometimes overwhelming
  • Best Uses: Day trips in GPS mode, weekly excursions (without GPS on), fitness training and tracking
  • Watch Examples: Suunto Ambit3 Peak, Garmin Fenix 5x Plus Sapphire, Suunto Traverse

The Gamin Fenix 5 Plus features (clockwise starting upper left) a compass  recovery time recommendation  activity data  a race finish prediction  elevation profile  and a weekly training load.
The Gamin Fenix 5 Plus features (clockwise starting upper left) a compass, recovery time recommendation, activity data, a race finish prediction, elevation profile, and a weekly training load.

Features: Take 'em or leave 'em?


You can get a watch that is either simple or chalked full of features. Some are also more accurate than others. So what do you need? If you're looking for the basic functions of an altimeter watch and training and fitness information, then you'll benefit from buying a watch with GPS and many other features. However, if you're just interested in just figuring out the time, your location, the altitude, and if there's weather moving into the area, a simple altimeter watch with basic features is truly all you need.

As is often the case with shiny new things, we found that features we had never previously considered became more and more useful as over time. This is to say if you are willing to splurge a little, opt for a model with additional features.

In this section, we outline key features that many altimeter watches include — all of the models that we tested come with a clock, alarm, compass, barometer, temperature gauge, and of course an altimeter. In addition to the basic features, we will also discuss some fancier features like GPS connectivity, social media data sharing, and more. Once you've learned about what an altimeter watch has to offer, and what to consider, check out our Best Altimeter Watch for Hikers and Backpacking review to make a selection.

Ryan enjoys the views of the high alpine tundra in the San Juan mountains. Hmmm...we wonder what altitude we're at...let's see!
Ryan enjoys the views of the high alpine tundra in the San Juan mountains. Hmmm...we wonder what altitude we're at...let's see!

Altimeter


If you're a hiker, backpacker, mountaineer, guide, or vertical athlete, knowing your altitude is the key function of an altimeter watch. For some, it may satisfy the curiosity of just knowing what elevation you're at, whereas for others it may help you find your location in a white-out storm. You can use it to calculate your vertical gain and loss throughout the day or to help you pinpoint your location. When considering an altimeter watch, it's important to consider the level of accuracy you require. For those who are generally curious about the figure, a less accurate (and potentially less precise) watch will probably do the trick. For those that are looking to pinpoint a location and calculate true vertical gain and loss for the day, you will have to pay a little extra for better accuracy.

How a watch altimeter works


Pilots use highly advanced and sensitive altimeters to figure out how high they are in the air…but how does it work? When it comes to watches, there are two ways to measure altitude. The first is using air pressure, and the second is using a GPS.

Air Pressure: Each watch that we tested is outfitted with at least a couple of sensors. The first is used to measure ambient air pressure. As you move higher in the atmosphere, the atmospheric air pressure decreases. Using this sensor and a reference to sea level ambient air pressure, the watch calculates altitude. The following equations are used to determine both barometric pressure and altitude in watches like the Suunto Core Alu, which allows you to change the reference sea level air pressure (most of the watches tested already have that value configured).

Absolute air pressure + Altitude reference = Sea level air pressure

Absolute air pressure + Sea level air pressure reference = Altitude

That said, if the weather (read: pressure) changes, the altitude reading will change as well, even if you don't change position. This is why watches should always be calibrated before starting a trip and throughout your trip, anytime you have a reliable reference point. If you encounter weather, continue to calibrate the altimeter manually at known sites (using either a map or elevation markers on the trail). If you travel to a different part of the world, make sure you calibrate the sea level air pressure reference to that area, as it changes based on where you are.

GPS: Global Positioning System (GPS) is a network of satellites orbiting Earth. Once your watch receives a signal from three of these satellites, your position can be triangulated. The more satellites that pick up a signal, the more accurate your positional data will be. GPS can be used to determine altitude based on previously logged data. However, these readings are not always precise. Many watches use both the GPS and air pressure function to determine altitude (e.g., the FusedAlti function in the GPS-equipped Suunto watches).

Make sure to calibrate your watch regularly to ensure great accuracy on your adventures.
Make sure to calibrate your watch regularly to ensure great accuracy on your adventures.

Calibrating your Altimeter Watch


Be sure to calibrate your watch manually to ensure greater accuracy along your trip. There are many opportunities to calibrate your watch, and you should take advantage of them when possible. If you're backpacking, you can use the contours on your paper map. If you're on a known summit with a known altitude or come across a sign with an elevation marker, you can calibrate it there. All of the watches that we tested allow you to calibrate altitude manually. If you don't complete these calibrations on a daily basis (or more often than that), you may find your altimeter reading is off — anywhere from a few hundred to a few thousand feet.

How does weather affect altitude readings?

Since altitude is calculated based on absolute air pressure as measured by the watch and a sea level air pressure reference, weather can easily change your altitude reading. This is especially true if you're in the mountains where weather conditions can fluctuate throughout the day. If you want to test this out, simply set your watch to a given altitude and leave it one place while weather moves in and out. If there is a decrease in pressure (a storm rolling in), the altitude will probably read lower than the actual. If there is an increase in pressure (nice weather moving in), the watch will probably read higher than it is.

Hiking in the high Andes required a recalibration before the trip. We looked at the sea level air pressure and changed our reference value to match so we could get accurate altimeter readings.
Hiking in the high Andes required a recalibration before the trip. We looked at the sea level air pressure and changed our reference value to match so we could get accurate altimeter readings.

How does latitude affect altitude readings?

Latitude and your location on the planet will affect how your watch calculates altitude. The air pressure at the poles is higher than the air pressure at the equator. Why? Because air pressure at the Earth's surface is determined by the mass of the air column above it. Since the equator receives more sun, the air is warmer and thus less dense (density = mass per unit volume) than it is towards the poles. As a result, the air pressure is lower.

On the other hand, the air is much colder at the poles and thus denser. As a result, the air pressure is higher. This trend stratifies from the equator out to each pole. And as a result, the air pressure at sea level changes with latitude. Make sure you check your local weather station or a local map to determine what the sea level air pressure is in your area and ensure this is entered into your watch (if your watch uses sea level air pressure to calculate altitude). Some watches don't allow you to change this value. If not, you should find out the barometric pressure where you are and manually enter it into your watch.

We love the large font and the options to change the watch from the digital format seen here to an analog format. We also liked the how the seconds are counted with the tick marks working their way around the face of the watch.
We love the large font and the options to change the watch from the digital format seen here to an analog format. We also liked the how the seconds are counted with the tick marks working their way around the face of the watch.

Timekeeping


First and foremost, a watch tells time. In this review, we encountered watches with atomic clocks, GPS time, and those with manual settings. Most watches tested provided a digital reading, except for the Casio PRW-6000Y. Atomic clocks are incredibly accurate and controlled by radio signals. In addition to an atomic clock, a few watches offer a world clock, allowing you to scroll through time zones around the world. If your watch does not have a GPS, you will need to manually change the zone when traveling. GPS-based time is easy — it always has the correct time and updates automatically as you cross time zones. Finally, some watches rely on traditional, manual timekeeping — set it at the beginning in reference to another clock, and change it manually if you move through different time zones. We think GPS timekeepers are the easiest to use, as long as you can get a good signal.

All the watches we tested come with a stopwatch, countdown function, and some sort of alarm. Some watches like the Casio SGW300-HB have five alarms, while most others like the Suunto Ambit3 Peak, have just one. We liked the additional alarms for longer days. Setting multiple can be helpful if you need daily reminders for lunch, medication, sleep, or wake up times. This is especially beneficial for longer trips. That said, many of testers felt like this was a nice extra, but not especially necessary.

The digital compass provides a directional reading in degrees.
The digital compass provides a directional reading in degrees.

Compass


The compass is a navigational and safety feature to have in case you need to determine your location and the direction you're traveling. Some watches allow you to set a point to navigate to, which can replace the need for a handheld GPS. (This is awesome!) GPS watches also include self-stabilization, which means you can get an accurate reading regardless of the angle of your wrist. All of the watches with a compass that we tested have tilt-compensated compasses (except for the Casio PRW-6000Y). This watch requires you to keep your wrist horizontal to get an accurate reading. In general, we like the tilt-compensated compass better as it is more accurate and easier to use.

A compass feature is great for a general point of reference. If you are doing more serious cross-country travel, we recommend bringing a traditional compass as well — it will be far more accurate. In addition, you need the straight edge of a compass to triangulate your route and estimate distances between your location and another visual destination.

Barometer


Why should you care about barometric pressure? The simple answer is that it helps you (and your watch) track weather and make educated predictions about incoming storms. Whether you're a hiker, guide, backpacker, or climber, you will benefit from having a mini-weather station attached to your wrist. Especially if you're stuck in a snow cave waiting out a bad storm or hiking through slot canyons in the desert. For folks at middle latitudes (e.g., the United States), if you lose four millibars of pressure in 12 hours, a storm is most likely on its way. If you lose six millibars in the same period, then it's going to be a big one. If you see a loss of eight or more millibars, go home and save yourself! Unfortunately, the barometers cannot predict when bad weather is going to end.

The barometric reading on the PRW-6000Y
The barometric reading on the PRW-6000Y

That said, if you see a trend of increasing pressure, you can hold out hope that the storm will break. All the models we tested could graph the barometric pressure except the Casio SGW300-HB. When looking for a watch, consider the interval of the barometer, whether it has a storm alarm, and how nice the barometric graph is. Of all the models we tested, we like the graphs on the Garmin Fenix 5X Plus the best, followed by the Suunto Ambit3 Peak and Suunto Traverse.

All the watches tested in this review used barometric units of hPa (hectopascal) and inHg (inches of mercury). You can choose the metric that better suits your preference.

Temperature


All of the watches we tested have a temperature display. We like the idea of this feature, but we learned that while wearing the watch, the sensors aren't very accurate. All of the watches read inaccurately because they are more or less measuring external skin temperature instead of the ambient air. Many of our testers noted that attaching the watch to the shoulder strap of a pack helped resolve this issue and provided a more accurate reading. In general, we didn't notice that any of the watches varied too much in temperature as long as we didn't wear them on our wrist.

If you're looking for an accurate temperature reading  wear your watch on your backpack strap! This way the heat from your wrist doesn't affect the temperature accuracy.
If you're looking for an accurate temperature reading, wear your watch on your backpack strap! This way the heat from your wrist doesn't affect the temperature accuracy.

Battery Life


Battery life is a crucial consideration for anybody heading out on a multi-day mission. When considering a purchase for an altimeter watch, look at how the watch is charged and the amount of time it lasts. Buying a watch with limited battery isn't any good when you need it for the long haul. A dead watch is a useless watch. When it comes to battery life, there are three options to consider: 1) traditional watch battery, 2) solar powered, and 3) USB charging. Each has their pros and cons, best for a specific function.

Traditional Watch Battery: A traditional watch battery is nice to have. It lasts longer and is far more reliable than USB charged watches. It's best for multi-day missions and can stay charged up to many years. That said, based on the power requirements of a watch, the battery life changes. The higher the performance of the watch, the more power it needs. The Suunto Core Alu, for example, has a battery that lasts only 12 months, while the simple Casio SGW300HB can last for up to three years. The Core has more accurate sensors, gathers more data, and has a much higher level of performance. As a result, it uses more battery life. The Casio SGW300HB is the opposite. It takes fewer data points and has limited functionality. As a result, it doesn't demand as much power, and its battery lasts a lot longer. Even though a regular watch battery is great, it can't support many features like GPS, fitness tracking, and connections to social media. That said, if you're worried about the battery dying on a trip, you can simply pack an extra.

The buttons are large  convex and easy to use with a pair of gloves. Here we see the left side of the watch with two buttons and the sensor. The right side of the watch has three buttons. This watch features just a simple watch battery.
The buttons are large, convex and easy to use with a pair of gloves. Here we see the left side of the watch with two buttons and the sensor. The right side of the watch has three buttons. This watch features just a simple watch battery.

Solar Powered: We loved the Casio PRW-6000Y and Casio PAG240B-2 for their solar charging capabilities. On long trips and throughout the life of the watch, there is no need to worry about charging. Just place it near a window or expose it to the sunlight for as little as six minutes a day and it will keep chugging on.

This Casio was the only one that had an analog time teller with a smaller digital window.
This Casio was the only one that had an analog time teller with a smaller digital window.

USB-Charged: The Garmin Fenix 5, Suunto Ambit3 Peak, and Suunto Core Traverse are all USB charged and feature GPS function. The upside to these watches is they have lots of features. These watches are designed to gather data — moving time, route information, navigation to a point, fitness tracking, and more. Most of these watches are geared more towards fitness tracking than anything else. Even though the data is nice to have on hand, the battery life truly sucks in comparison to solar powered and regular watch battery models. When GPS is on, watches will last anywhere from just eight hours to 50 hours (based on the settings and your location). For most multi-day adventures, this isn't long enough to keep GPS function on the whole time. So you must be diligent to turn the GPS function off when it's not needed. If you're looking for something that can track a route for days, a Handheld GPS may be your best bet instead. That said, when GPS is off, a watch can last anywhere from just 14 days to six weeks (based on the model). Overall, these watches feature more perks, but the battery life is a serious tradeoff to consider.

A comparison of both altitude  and battery life. Both watches started fully charged. The Traverse shows almost 50 percent less battery life than the Suunto Ambit3 Peak on this hike.
A comparison of both altitude, and battery life. Both watches started fully charged. The Traverse shows almost 50 percent less battery life than the Suunto Ambit3 Peak on this hike.

Overall, when considering your watch purchase, determine what kind of battery life you need to make an informed decision. Take a look at our comparison chart in our best in class review to see a direct comparison of battery life and types of batteries used.

GPS Function


Having GPS is a great way to see your moving metrics. Some folks are truly interested in this information, while others just aren't. One of the big pros of any GPS watch is the features. Moving speed, vertical climb and descent, route information, high and low points, fitness trackers, virtual fitness pacers, virtual games, pace metronomes, and more, are all features that you'd find in high-end GPS altimeter watches.

A look at the GPS function on the Garmin Fenix 3 while taking a short bike ride out of town.
A look at the GPS function on the Garmin Fenix 3 while taking a short bike ride out of town.

Also, you can connect to apps like Strava, Garmin Connect, and Suunto Movescount to help you track your fitness routines. You can also use these apps to upload routes to your watch with predetermined waypoints. All you need to do is follow the route for a new adventure — a cool feature, especially if you're traveling and want to explore a place by yourself. The only challenge that a GPS watch faces is a lack of battery life (as mentioned above). Turning on GPS function quickly drains the battery, making these watches a lot less reliable than the rest, and not the best option for multi-day missions (if you plan on running GPS the whole time). To learn more about GPS watches for fitness training, check out our The Best GPS Watch for Running and Training review.

Accessories


In addition to the plethora of features, one should also consider the accessories to go along with it. Heart rate monitors are a great way to track personal performance. It's perfect for any athlete in training or any recreationist that likes to see what their body is doing. In addition, you can also find compatible foot pods for more accurate pace and distance information (best for runners). For some models, bike pods can also track cadence and speed more efficiently than just GPS.

A look at the traditional variety. Left to right: Casio PRW6000Y (solar powered)  Suunto Core Alu (battery)  Casio SGW300HB (battery)
A look at the traditional variety. Left to right: Casio PRW6000Y (solar powered), Suunto Core Alu (battery), Casio SGW300HB (battery)

Additional Considerations


When looking for your next altimeter watch, features aren't the only thing to consider. You should also look at its durability and functionality for all conditions. Here are a few other top tips to consider when looking for an altimeter watch:

1) Look for a watch with mineral glass. This heat-hardened material is less prone to scratches and wear.

2) Choose rubber straps with many holes. These straps are typically a little more durable, versatile, and comfortable. They also feel more comfortable and flex around clothing more easily. A watch that sports more holes is far more breathable and won't feel itchy or hot on your wrist.

3) Consider the size of the watch display. A larger face makes it easier to see in poor conditions. A smaller display will feel a little more comfortable on the wrist but is less functional when you need to sneak a quick peek.

This shows the right side of the watch  with two buttons. All the buttons are spaced far apart enough to be used with gloves. In addition  you can see where the sensor is located (between the buttons).
This shows the right side of the watch, with two buttons. All the buttons are spaced far apart enough to be used with gloves. In addition, you can see where the sensor is located (between the buttons).

4) Choose a watch with large buttons. If you're planning on a winter adventure, make sure to choose a watch that is compatible with gloves. In our testing, we looked at each watch to see how well it could be used with a pair of gloves. We learned that the bigger the buttons, and the further spaced apart they are, the better.

5) Choose a long wristband. If you have a choice of wristbands, make sure you choose the longer option. In some cases, you may want to wear it on the outside of your jacket. Also, make sure the band has enough holes for the tongue to fit through — especially if you have a smaller wrist.

6) Wear it medallion-style. In a casual conversation with a couple of mountain guides, they mentioned that wearing the watch around their neck is a classic option. This helps to ensure the temperature, altitude, and barometric gauge are more accurate with better viewing access. We thought we'd pass it along to other outdoor enthusiasts as well.


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