GPS in watches and fitness trackers: what is it and why does it matter?

GPS stands for Global Positioning System, and according to the official website it is a “U.S.-owned utility that provides users with positioning, navigation, and timing (PNT) services”.

Its satellites were originally used for military purposes, but in the 1980s they were made available for civilian use. The system currently uses a minimum of 24 satellites and lets users access the service around the world. 

GPS specifically refers to the system controlled by the United States but is often used as shorthand for global navigational satellite systems (GNSS) in general, including Galileo (Europe’s GNSS system), GLONASS (a Russian equivalent) and BeiDou (a Chinese system). 

GPS, or any GNSS, allows a user to calculate their location, how far they’ve travelled and how quickly. Whether you are navigating your way around a new city, going hill walking, or running in your local area, GPS can track your position with a high degree of accuracy.  

As we mentioned above, GPS and other GNSS systems make use of satellites to find your location. The satellites each follow a precise orbit and send a unique signal so your GPS device can tell which satellite it is talking to. 

Your device will work out how long it takes to receive a signal from each satellite it connects with. And by connecting to the signal of at least three satellites, it can work out where it is in relation to those satellites, giving you your latitude and longitude. This process is commonly called triangulation, but is more accurately described as trilateration.    

If your device can connect to four or more satellites, it can also then calculate your altitude as well as your latitude and longitude. And, having found where you are, GPS can then work out some other metrics, such as: 

• Your speed 
• Direction of travel 
• Distance covered 

Many smartwatches and running watches will connect to more than four satellites, and will even use a variety of GNSS to ensure accuracy. It also means that if, for example, your GPS signal can’t connect, it may be able to find a GLONASS or Galileo connection instead.

This means that some more expensive devices could be tracking more than 20 different satellites.

Depending on what type you have, your smartwatch or fitness tracker will usually offer one of two types of GPS functionality: built-in GPS, or connected GPS. While the general principle is the same, they work slightly differently. 

As the name suggests, a device with built-in GPS, like the Samsung Galaxy Watch 5,Fitbit Charge 5 or Xiaomi Smart Band 7 Pro, means that it communicates directly with whichever GNSS it is set up to connect with.

This means that once you start tracking your walk or run, for example, your wearable will continue tracking your movements for as long as you ask it to. 

Connected GPS means that your fitness tracker or watch doesn’t have its own GPS capability. Instead, it relies on the GPS in your smartphone to track your location. Usually, this means the device will be slightly cheaper as it doesn’t require its own GPS components.  

As such, tracking accuracy may be compromised if for some reason your phone struggles to get a GPS connection compared to a watch with built-in GPS. There’s also the fact that GPS built into a fitness tracker or watch is designed specifically to track your movements. In a phone, the GPS may be less optimised for this purpose.

We’ve tested some connected GPS devices, such as the Garmin Vivosmart 5 (pictured above), which is very precise. But we’ve also tested others, like the Polar Unite, which have been less reliable.

It does also mean that you’ll need to take your phone with you when you go out to exercise, which can be a hassle.  

Of course, not everyone will need built-in GPS. It really helps anyone who wants to track outdoor sports and activities, such as running, cycling, hiking, or wild swimming 

If you do most of your exercise indoors, or focus more on activities such as strength training, yoga or Pilates, which don’t really require GPS tracking, then you may not need built-in GPS (or indeed any GPS at all).

As we’ll see, there are many reasons to choose a device with GPS functionality, whether that’s built-in or connected. But there are potential drawbacks to consider as well. 

You may not have considered GPS as a major factor when considering what wearable to buy. But there are some potentially good reasons to make sure you have this feature available. 

A GPS-equipped smartwatch or fitness tracker will usually give you far more accurate data than one that doesn’t have GPS. The system is often precise to within 10 metres, but in open spaces it could be even more accurate.  

Accuracy matters for several reasons, but primarily in this context it tells you how far you’ve travelled and how quickly. Maybe you want to train for a 5k. In that example, knowing how far you’ve run can be invaluable in measuring your progress towards that goal. The same applies to any other run, bike ride or swim. 

Of course, if you’re trying to get fitter then knowing how far you’ve travelled isn’t the only metric that matters. And linked to the accuracy of GPS is the fact you’ll be able to access other data as well. This includes things like your average speed, which is often broken down into split times on devices such as the Coros Pace 2 or Garmin Venu 2. 

Compare this to a device that doesn’t have GPS: it won’t be able to accurately gauge how quickly you went or how far you’ve travelled (any estimate will be based on your step count, for example). 

GPS-enabled devices may also help with your motivation, as seeing your previous distance and pace helps shape your ambitions for next time. You’ll be able to see progress and improvements over time and be confident that you are getting correct information. 

While there are many benefits to having GPS in your smartwatch or fitness tracker, there are some drawbacks: 

As we highlighted earlier, devices with built-in GPS, such as the Fitbit Charge 5, do tend to be more expensive than broadly comparable devices that don’t have GPS, like the Fitbit Inspire 3. Extra features and components do push up the price.

Secondly, being in constant contact with multiple satellites does have a significant impact on the battery life of your fitness tracker or smartwatch. To use the Garmin Venu 2 as an example, without GPS, Garmin says you may get up to 11 days of battery life. With GPS mode on, that drops to a maximum of 22 hours. It’s a big difference, even if it won’t necessarily affect you unless you are using GPS a lot. 

Ultimately, the value of having GPS in your device will come down to how you intend to use it. If you workout outdoors and want to accurately track their exercise, we’d regard GPS as a “must-have” feature.  

On the other hand, if you don’t want to track your walks, runs and bike rides, or you do all your exercise indoors, then GPS will be far less important and less useful to you.  

If it’s something you’re interested in exploring further, our guide to the best budget fitness trackers will tell you which devices will give you the most precise GPS tracking, without breaking the bank.

And if you aren’t sure what type of device you need, our fitness tracker vs smartwatch guide will help explain the other major differences between them.