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Best activity trackers and fitness watches

Top 5 best fitness watches and activity trackers with heart-rate monitors

By Hannah Walsh

Article 4 of 6

We review the latest and greatest fitness watches and activity trackers with built-in heart-rate monitors from all the top brands

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

A built-in heart-rate monitor is a useful feature and, if accurate, can help you track your active heart-rate zone and measure improvements in training. We’ve tested fitness watches and activity trackers with built-in heart-rate monitors from brands including Fitbit, Garmin, Polar and Samsung, among others.

The Best Buy fitness watches and activity trackers in the table below not only do a great job of accurately tracking your heart rate and other activities, but are comfortable to wear and a breeze to use, too. 

Poor performers in our tests struggle to accurately track heart rate, including one device that understated it by nearly 60%.

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Best fitness watches and acitivity trackers with heart-rate monitors


Heart-rate tracking combined with plenty of features and accurate tracking will make this fitness watch music to your ears.


This comfortable activity tracker has great functionality, including built-in GPS and a built-in heart-rate monitor. Activity and heart-rate tracking is accurate – is it the tracker for you?


This tracker is packed with features, including a built-in heart-rate monitor and GPS sensor. It scored five stars for heart-rate monitoring accuracy.


This fitness watch looks basic but it packs a punch. It’s well-made and accurate, and has useful features for beginners and more-experienced runners alike.


We got 15 days of battery life from this fitness tracker and found it well-suited to runners.

Pricing, recommendations and test scores correct as of June 2018.

Not found the perfect product for you? Browse all of our fitness watch and activity tracker reviews.

How do we test heart-rate tracking accuracy?

Our test participants go through a series of tasks while wearing a ‘telemetry monitor’ chest strap, which measures the electrical signals from their heart. They walk on a calibrated treadmill at 4.8km/hour for 10min and run at 9-10km/hour for 10 min and go through a routine of daily tasks, including loading and unloading a dishwasher, carrying the shopping and sitting reading a magazine.

We compare the heart-rate readings from the telemetry monitor with the fitness watch or activity tracker, which allows us to calculate how accurate the device is. We know consistency is just as important as accuracy, particularly when using changes in heart rate to monitor improvements in fitness over time. So we repeat our walking test to see if the trackers consistently overstate, understate or hit the accuracy mark.