What is the most accurate smartwatch for heart rate?

Polar / Gamin / Coros / Apple / Oura

Tracking your heart rate during workouts is one of the best ways to maximize each session -- while also making sure you don't push yourself past your limits. But the key to using heart rate data effectively is making sure you have the best heart rate monitor.

At a minimum, your heart rate monitor should accurately measure your heart rate to within a few beats per minute. But you also need a gadget that's durable and compatible with your favorite smartwatch or fitness app so you can access that data easily mid-workout.

Whether you want a waterproof, precision chest strap to wear during workouts or a super comfortable heart rate monitor you can wear all day long, here are our top five favorite heart rate monitors to get for 2024.

Best heart rate monitor overall: Polar H10

Polar

Widely regarded as the most accurate, commercially available heart rate monitor, this Polar chest strap is often the benchmark against which other devices are compared. Rather than optical sensors (like those used on most smartwatches or fitness trackers), the chest strap uses an electrocardiogram (ECG) -- small electrodes that pick up electrical activity -- to measure your heart rate.

Since it's a chest strap, those electrodes are worn right next to your heart for the most precise measurement possible outside of a hospital.

In addition to accuracy, the Polar H10 boasts a soft textile strap and non-slip silicone patches that keep it in place, even while you're working out. Speaking of workouts, the heart rate monitor is waterproof down to 30 meters so you can swim, work up a sweat, and shower without worrying about your chest strap.

Plus, this latest generation adds improved connectivity, allowing you to sync your data with a variety of fitness apps and even pair it with your stationary bike. While the chest strap is regularly listed at $90 when you buy it directly from Polar, you can get it for as little as $74 on Amazon.

Top features of the Polar H10:

• The best-in-class heart rate monitor boasts the best accuracy outside of a medical ECG machine.
• Waterproof down to 30 meters, the chest strap can be worn during any workout, including swimming.
• You can easily sync your data with Peloton, Strava, Nike, Apple Fitness+ and other popular health and fitness apps.
• The built-in memory lets you log data during your workout with just the chest strap, so you can leave your phone at home and sync the data when you're done.  
• The battery lasts up to 400 hours.

Get Polar accuracy for less: Polar H9

Amazon

If you want the accuracy, durability and battery life of a Polar chest strap without the price tag, try the previous generation Polar H9. 

Like the latest generation chest strap, the Polar H9 uses an ECG to track heart rate so you get the same accuracy. It also uses the same battery and boasts the same waterproof design. 

The main downgrades are the lack of multipoint Bluetooth pairing and built-in memory for storing your health and training data. If you're willing to give up those features, you can get the Polar H9 for as low as $60 on Amazon.

Best heart rate monitor for runners: Garmin HRM-Pro Plus

Amazon

The Garmin HRM-Pro Plus was built for high-intensity cardio. Beyond heart rate tracking, the comfortable, non-slip chest strap also tracks key running dynamics like vertical oscillation, stride length, ground contact time and vertical ratio to give you more in-depth insights into your runs.

For runners who prefer to run unencumbered, the chest strap has built-in memory, so you can leave your phone (and even your Garmin fitness tracker) at home and sync the data when you get back. If you do have your phone or smartwatch with you, the chest strap can transmit real-time data to compatible devices so you can check your heart rate as you work out.

Get the advanced Garmin heart rate monitor while it's on sale at Amazon for just $92 (reduced from $130).

Top features of the Garmin HRM-Pro Plus:

• Get accurate, real-time heart rate data transmitted to your phone or smartwatch during workouts.
• The built-in memory can track your workout on its own and sync the data later if you prefer to workout without your phone.
• Runners can also track tons of key running dynamics data whether they're outdoors or on a treadmill.
• With a 5 ATM waterproof rating, this heart rate monitor is also swimproof.

Most comfortable heart rate monitor: Oura Ring (Generation 3)

Oura

The Oura Ring is one of the most stylish and easy-to-wear heart rate monitors on the market. Packed into an elegant titanium ring, you'll find an optical heart rate sensor as well as sensors that track blood oxygen, body temperature and activity.

In addition to tracking advanced health data 24/7, the Oura Ring is also durable enough (and comfortable enough) to wear while working out. While it's not recommended for lifting weights -- you might scratch the ring -- it's great to wear while running, biking, dancing or even during a HIIT workout.

With the ability to automatically detect over 40 workout types, you're free to start working out without your phone or other device nearby--and if it ever gets the activity type wrong, you can edit the logged workout in the app.

Its unique design also makes it the easiest heart rate monitor to wear while sleeping. So if you're looking for an alternative to a watch or chest strap to wear while you sleep, this is it.  

Prices start at $299 for the sleek, stylish Oura Ring.

Top features of the Oura Ring:

• The ring is comfortable enough to wear all day (and all night) for 24/7 tracking of all your key health metrics.
• Get a personalized daily readiness score based on your sleep quality, health data and workout history.
• The built-in sensors track heart rate, blood oxygen, body temperature, steps and activity.
• Get robust sleep tracking features including a sleep stages chart, breathing graph, heart rate variability data and overall sleep score.
• The battery lasts up to seven days in between charges, even when wearing it all day.  

Best heart rate monitor armband: Coros heart rate monitor

REI

If you don't like the feel of wearing a chest strap, this Coros heart rate monitor armband is a great alternative. Worn up on your bicep, it's soft, snug and stays out of the way as you run, swim or lift weights.

While its position further from your heart means it's not quite as precise as the Polar H10 or Garmin HRM-Pro Plus, it's still accurate enough to rely on for heart rate zone training and tracking general trends in your heart rate.

Plus, it's rechargeable--unlike either the Polar or Garmin chest straps, which require users to replace the battery when it dies. It also has wear detection to help it avoid draining the battery by automatically powering it on and off when you put it on or take it off. That wear detection even allows it to automatically pair with a connected device when you put it on. So just slip on the armband and you're ready to work out.

Get the comfortable, rechargeable Coros heart rate monitor for $79 at REI.

Top features of the Coros heart rate monitor:

• Multipoint pairing allows you to transmit real-time data to up to three devices - including treadmills, stationary bikes and other home gym equipment along with your smartwatch or phone.
• The battery lasts up to 38 hours and can be recharged so there's no need to replace the battery.
• Wear detection will automatically power it on and sync to your connected device as soon as you slip it on your arm (and then power itself off when you take it off).

Best smartwatch for monitoring heart rate: Apple Watch Series 9

Amazon

One of the best smartwatches for heart health monitoring, the Apple Watch has consistently ranked among the most accurate for heart rate tracking in multiple studies. It's the next best thing to a chest strap, so if you don't find those straps comfortable--or you want something you can wear all day--the Apple Watch 9 is the one to get.

With the new Siri Health upgrade, checking your heart rate and other health data is as easy as asking Siri. You can also use Siri to start a new workout and get status updates along the way. Instead of navigating the watch screen, just say "Siri, start an outdoor run workout" or "Siri, start a yoga workout." Your new watch will immediately start tracking the activity, even when you're not connected to Wi-Fi or a cellular network.

The Apple Watch 9 is at the center of an international trade dispute between Apple and another tech company, but as of now, you can still get it at Amazon and Walmart.

The latest Apple Watch is on sale at Amazon right now Prices start at $349 for the 41mm size (reduced from $399).

Top features of the Apple Watch Series 9:

• Multiple studies have confirmed that the Apple Watch offers the most accurate heart rate tracking in a smartwatch.
• You can take an ECG anytime.
• Advanced tracking features give you a clearer picture of multiple health metrics, in addition to heart rate.
• Access tons of workouts through the Apple Fitness+ app and follow them from your watch.

Shop more top-rated heart rate monitors

A lot of us use our smartwatches and fitness trackers to track important health metrics, like how well we slept or whether our stress levels are high. Many of those insights wouldn’t be possible without heart rate tracking. "It's really the basis for so much," says DeCarlos Love, a wearables product manager who works on Google Pixel Watch and Fitbit devices.

When Google acquired Fitbit in 2019, the wearables team knew that bringing in deep expertise with wearables and a history of heart rate tracking would benefit future products — like the Google Pixel Watch. Now, the just-launched Google Pixel Watch 2 and Fitbit Charge 6 both feature our most accurate heart rate tracking yet on a smartwatch and tracker . Here’s what’s going on underneath the hood that makes it all possible.

It starts with sensors

If you, like me, thought that smartwatches and fitness trackers measured heart rate by feeling that “bump bump bump” vibration of your pulse on your wrist, you would be wrong. Well, sort of wrong. “When you think of taking someone’s pulse, you imagine putting two fingers on their neck and picking up on the beat or vibration of their heart,” DeCarlos says. “But with heart rate sensors, that’s not quite what they’re doing.” Instead of feeling something, the sensor is seeing something.

Specifically, a PPG sensor — PPG is short for photoplethysmography. A PPG sensor uses light to measure the volume and movement of your blood circulation. It does that by shining a green LED light onto your wrist, which then reflects the movement of your blood back to the sensor. “We pick up that rate of reflection and we’re able to understand how your blood is flowing — aka, your heart rate,” DeCarlos says.

While the original Pixel Watch had a single path PPG sensor, the new Pixel Watch 2 features a brand new multi-path LED sensor. Having multiple LED and photodiodes (a device that detects the amount of light reflected by blood) helps the watch cover more surface area on your skin, DeCarlos says, which gives you more accurate recordings when all sensors are activated.