Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag still brings the looks, but it needs the great smarts to match it
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Tag Heuer Connected Calibre E4
By Tag Heuer
The Tag Heuer Connected Calibre E4 is a beautiful smartwatch, regardless whether you choose the 45mm or 42mm size. But as ever, you can access most of these features – and better fitness smarts – for a fraction of the price elsewhere. Ultimately, the Tag Heuer Connected Calibre E4 is about status, quality and craftsmanship. But Wear OS 3.0 now need to step up to the plate.

  • Beautiful design and materials
  • Zippy software performance
  • Lovely Tag watch faces
  • Not running Wear OS 3.0 (yet)
  • Heart rate tracking is poor
  • Battery improvements negligable

Swiss horology icon Tag Heuer is back with the Connected Calibre E4 – its fourth generation Wear OS smartwatch.

When the original Tag Heuer Connected was launched back in 2016, few gave the project much chance of success. But despite the headwinds of limited Wear OS/Android Wear success and Apple hegemony, Tag Heuer has forged ahead with its Swiss-made smartwatch.

The Tag Heuer Calibre E4 comes in two different size options: the 45mm and a new-look 42mm version. Both run on Wear OS 2.0, with a Wear OS 3.0 update promised for later in the year.

Outside of the Tag Heuer look and feel, the Calibre E4 bolsters its fitness tracking credentials, with new guided workouts, dedicated golf app and 30% more battery.

Here's our comprehensive review of the Tag Heuer Connected Calibre E4.

Tag Heuer Connected Calibre E4 price:

The smallest 42mm Tag Heuer Calibre E4 costs $1,800/£1,500 – and that rises to $2,250/£2,200 for the 45mm.

In terms of cost its relatively unmatched. There have been options such as the Montblanc Summit Lite ($700) and the Hublot Big Bang e ($4,200) – both of which run Wear OS...but neither are due to get the big upgrade this year.

Tag Heuer Connected Calibre E4: Design and screen

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (42mm version)

Tag Heuer has always nailed the quality and desirability of its Connected smartwatches – and that does not change with the Calibre E4.

The Calibre E4 45mm come with four different looks and that includes a golf themed edition.

You get a stainless steel case with a lovely ceramic bezel, and it measures in at 15.3mm thick, so it's by no means the slimmest smartwatch. Tag watches aren't designed to be slim, and the Calibre E4 45mm embraces that design language. It's all about the heft, and the E4 is definitely a smartwatch you notice when it's on.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (45mm version)

Our watch case was matched up with a rubber strap, that is removable thank to a similar clasp mechanism that you find on some of Garmin's top end watches. It uses a clasp and button mechanism to hold it in place and while it's a bit of an awkward customer at first, it does feel secure. We could have done with a bit of strap though as it struggled to offer a completely snug fit on our slimmer wrists.

If you want to buy additional straps for it as well, you're looking at £200/$200 for another rubber strap or just over $400/£400 for a metal bracelet-style one.

On the side of the watch case, Tag has stuck with a combination of rotating watch crown with its signature logo engraved, and two physical pushers.

Tag has refined those pushers to give them a mechanical watch feel, and they certainly deliver on that front.

What's more satisfying is the mechanical click of the crown, which has also beeb given an overhaul.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (45mm version)

There's a good-sized 1.39-inch, 454 x 454 pixel resolution touchscreen AMOLED display that can be kept on at all times and is basically the same screen size and resolution you'll find on something cheaper like the TicWatch Pro 3. On the Calibre E4 it performs where it matters offering a nice, bright, colourful display that doesn't struggle for visibility in bright direct sunlight.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (42mm version)

Switch over to the 42mm Calibre E4 and you've got a similarly sleek, stylish look that does give you the feel of a luxury watch let alone a luxury smartwatch.

It comes in three different looks, with a steel case that measures in at just under 14mm thick, and features a removable strap. It still carries that luxury watch heft and has those mechanical push buttons on the side to accompany the touchscreen display.

That screen is a smaller, with a 1.28-inch, 412x412 resolution AMOLED display in place, which can be set to an always-on display mode. Despite the drop down in size and resolution, it's still a pleasingly sharp, colorful screen to gaze at and when it's not in always-on mode, the raise to wake gesture is nicely responsive.

Both watches have been tagged with a 5ATM certified water resistant rating. That does mean you can submerge them in water up to 50 metres depth. We've kept them on the shower and hit the pool with the 45mm version and they've remained fully functioning after.

We'd be inclined to say the smaller 42mm version was nicer to wear, simply because it was a better fit for our slimmer wrists. There will be plenty of Tag fans though who will appreciate the bigger frame of the 45mm Calibre E4.

While this is certainly one of the best-looking smartwatches and makes you feel like a watch of a high value, this is something Tag refers to as a luxury sports watch. Getting comfortable with running, swimming and working out with this watch takes some getting accustomed to.

This isn't like working out with an Apple Watch or a Samsung Galaxy Watch 4. You can't help but feel precious about wearing it, given its value.

Tag Heuer Connected Calibre E4: Wear OS

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (45mm version)

The Calibre E4 will run on Google's latest Wear OS 3.0, we just don't know when. For now you're stuck with tired old Wear OS 2.0 – and that's certainly frustrating.

Tag has included some of its own software here too, mainly on the fitness front and does include its own array of watch faces, which do always help to elevate the look of the watch and make it feel a bit more premium. And Google has launched a final update for Wear 2.0 with some improvements to tide us over during Wear 3.0's glacial launch.

Qualcomm's latest Snapdragon Wear 4100+ processor runs the show here, along with 1GB of RAM and 4GB of storage on both watches. It's standard tech for current Wear watches, but keeps things lovely and slick on the performance front.

There isn't any horrible lag swiping through screens or achingly long waits for apps to launch, as has been the case in the past.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (42mm version)

We spent the majority of our testing time with the watch paired to an Android phone, which provides the most complete software experience. You can make full use of the music features and respond to notifications and the experience of using it overall was fine.

The real issue here is that the software as a whole can feel a bit disjointed just in terms of how elements connect and even where things live on Wear OS. Swiping right to get to access a screen dedicated to Google Assistant feels a bit of a waste of space. Google's suite of apps just don't feel very polished. Notification support works well, but it just feels like other smartwatch platforms execute that crucial smartwatch a lot nicer.

All the Wear staples like Google Pay, music features, app support remain the same as what we've tested on other recent Wear watches.

It's great that there's now more than one music streaming service that supports offline playlist support for Wear and music playback controls work well here too.

Things you miss out on here really that you get from other smartwatches is the LTE support and the ability to take calls via Bluetooth, which is on offer on other Wear watches.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

We do need to reserve some time to talk about watch faces, specifically the official ones that Tag offer on the watch and via its Connected companion phone app. You'll need to download this as well if you want to dig into your health and fitness data, but it's also the place where you can get access to Tag's lovely array of watch faces.

Of all the Wear OS hardware partners, it's arguably Tag that has impressed us the most with its attention to detail with the digital and analogue-style watch faces it offers. There's a lovely collection here, embracing the dials of the classic watches in Tag Heuer's iconic range.

While we don't entirely love Wear OS, its issues are definitely more bearable on the Calibre E4 than it is with most watches. You do still get the processing power to keep things slick, most features work well enough and you've got those great collection of watch faces too.

Much hinges on Wear OS 3.0 and how that ultimately changes the experience and whether it changes things for the better. We sincerely hope so because the Calibre E4 deserves better than the ageing Wear OS 2.0.

Tag Heuer Connected Calibre E4: Fitness and sports tracking

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (42mm version)

If you're an owner of a normal Tag Heuer watch, you'd probably wouldn't consider stepping into a gym with it on your wrist, But the watchmaker wants you to keep on the Calibre E4 when it's exercise time.

Along with offering access to Google's own suite of Fit apps, Tag also offers its own Sports app. This has been improved, and it's added a Wellness app, dedicated to tracking steps and daily heart rate.

The Calibre E4 does do a decent job of tracking basic workouts, but it simply doesn't match what you'd get from dedicated sports watches – or fitness orientated smartwatches such as the Apple Watch or the Huawei Watch GT 3.

You do at least get the key sensors. There's an optical heart rate monitor on board to track heart rate continuously and during exercise. And there's GPS to track outdoor workouts, and it utilizes the standard motion sensors found in most connected watches to track activities including swimming.

Focusing mainly on Tag's own sports app, you do get a nice slick interface. You can quickly swipe through the supported modes, which now adds a treadmill mode, which was missing from the app when it first appeared on the Tag Heuer Connected 2020. There's also pool swimming, cycling and a golf tracking mode here too.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

GPS tracking compared: Tag Heuer Calibre E4 (left and centre) and Garmin Epix 2 (right)

Performance-wise, using the Calibre E4 as a running watch was pretty similar to what it was like with the Connected 2020.

GPS accuracy was passable – and against a Garmin Epix produced a similar recorded distance. On longer runs we did find the Tag Heuer tended to record slightly more distances, but well within the margin for error you need to consider when testing GPS out in the real world.

Heart rate tracking during workouts was less impressive. Even on steady paced runs, and it reported maximum and average readings 10-15bpm off a chest strap monitor. It can be hard to get a good fit when a smartwatch is so chunky, and it leaves question marks over the sensor tech too. In the unlikely event you're buying the Calibre E4 to track workouts, perhaps rethink your choices.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

HR tracking compared: Tag Heuer Calibre E4 (left) and Wahoo Tickr HR chest strap (right)

In the water tracking swims, the screen is locked to make sure that touchscreen doesn't jump into action as you get moving.

We found distance tracking from the 45mm version matched up with the Polar Pacer Pro watch, though it offered a slower average pace time in comparison.

The collection of stats is nicely presented inside of the Connected app, including SWOLF scores, stroke counts and a closer look at your pace insights.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Swim tracking compared: Tag Heuer Calibre E4 (left and centre) and Garmin Epix 2 (right)

The big new addition is an improved fitness mode, which now allows you to follow animated workouts on screen in a similar manner to Huawei and Garmin's latest watches.

You still have a basic fitness mode that captures heart rate and workout duration, but now you can pick from short, 7-minute workouts that let you focus on strengthening your core or working on your upper body with some pretty simple set of bodyweight based moves.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (45mm version)

The execution of the animated workouts is great and is a nice addition here though not a groundbreaking feature in smartwatch terms.

Tag does offer the ability to create your own workouts too, though we struggled to find the support to do that in the Connected app when prompted to head to that app to set things all up.

Along with that Sports app you also get a new Wellness app, which is more about your standard fitness tracking.

This is a watch that's capable of counting daily steps, estimate calorie burn and keeping continuous tabs on your heart rate. There's isn't native sleep tracking, so you'll need to delve into the Google Play Store if you want to take this luxury watch to bed with you.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

For step counts, we wore the Calibre E4 alongside the Oura Ring 3 and the Garmin Epix and found that daily step counts in general were around 1,000 steps of what those other devices recorded. All of these devices rely on different algorithms to calculate those counts and we'd say accuracy-wise, the Calibre E4 was there and thereabouts – and we had no concerns about accuracy.

If you care about tracking your heart, we'd say that isn't a particular strength with this watch. Just as it wasn't so great for exercise, we found that readings in the Wellness section of the Connected app were usually 20bpm higher when compared to the very reliable continuous HR monitoring support on Garmin's watch, and the Oura Ring 3.

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Heart rate tracking compared: Tag Heuer Calibre E4 (left) and Oura Ring 3 (right)

A nice added bonus is that you do have the option to share data to Strava and Google Fit, so if you don't love poring over your stats in the Connected app, you do have alternative places to crunch the numbers.

In the quest to make its smartwatch feel like one you'd turn to help keep you fit, we'd say it's very much still a work in progress. Hopefully Wear OS 3.0 with that expected heavy Fitbit influence will improve things – but health and fitness isn't the Calibre E4's strength.

Tag Heuer Connected Calibre E4: Battery life

Tag Heuer Connected Calibre E4 review (42mm & 45mm tested)

Tag Heuer Calibre E4 (45mm version)

The 42mm version features a 330mAh capacity battery that should give you a full day of battery, which includes an 1 hour and 30 minutes of run tracking.

The 45mm version has a larger 440mAh battery that also delivers a day od battery, which includes an hour of sports tracking.

In our testing with the 45mm version, we found that with the screen not set to always-on, heart rate being continuously monitored, notifications enabled and with 30 minutes of GPS use, daily battery drop-off was about 50-60%, leaving you a bit spare for using it the following day. With the 42mm version, it was close to exhaustion after a busy day.

When it does try to get two days on the 45mm version, it will switch to the clock mode, leaving you with zero access to the onboard smart features. It never made it to a full two days in our testing, so we'd say a maximum of a day and half with that clock mode is what you should expect here.

There's no quick charging mode here, so you're looking at dropping it onto its proprietary charging cradle for an hour and 30 minutes to go from 0-100% on both watches.

There is definitely a noticeable improvement on the battery performance with the larger Calibre E4, but it's a very small improvement when you consider there are plenty of cheaper smartwatches that can go for much longer.

How we test

Michael Sawh


Michael Sawh has been covering the wearable tech industry since the very first Fitbit landed back in 2011. Previously the resident wearable tech expert at Trusted Reviews, he also marshaled the features section of T3.com.

He also regularly contributed to T3 magazine when they needed someone to talk about fitness trackers, running watches, headphones, tablets, and phones.

Michael writes for GQ, Wired, Coach Mag, Metro, MSN, BBC Focus, Stuff, TechRadar and has made several appearances on the BBC Travel Show to talk all things tech. 

Michael is a lover of all things sports and fitness-tech related, clocking up over 15 marathons and has put in serious hours in the pool all in the name of testing every fitness wearable going. Expect to see him with a minimum of two wearables at any given time.

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