Apple Watch features a heart rate monitor to help guide you through your workout sessions, tracking your heart rate while you exercise to better determine the amount of calories you burn during your activities.

The monitor also automatically tries to measure your heart rate every 10 minutes, but doesn’t record the data if your arm is moving. That is why your Health app doesn't reflect a reading at every 10 minutes on the dot, but shows varying intervals of readings.

Apple Watch Heart Rate Monitor 1
If you want to get a quick, accurate measurement of your heart rate manually you can do so in Glances.

The heart rate sensor is on the backside of the Apple Watch case and is made up of two different sets of special lights that monitor the blood flow through your wrist. Because the sensors absorb light through your skin, there are a few factors that affect the accuracy of a heart rate reading.

Apple Watch Heart Rate Sensor 2
By following a few tips, as well as calibrating Apple Watch for workouts, you will get a better heart rate reading, thus improving the device's ability to more determine how many calories you burn.

A Proper Fit

As simple as it sounds, a good fit is key to getting an accurate heart rate reading. Some people don't like the way it feels to have their watch snug on their wrist, but for the purposes of a proper reading, you'll need to keep it tight. When you hold your wrist out, there should be no gap between Apple Watch and your skin.

Apple Watch Correct Fit
If the feeling is just too uncomfortable for you to wear the device snug to your wrist, it might be a good idea to adjust the band differently for different activities. If you are working out, tighten it up one notch until you are done.

Avoid Cold Weather Workouts

The heart rate sensor is affected by how much blood flows through your skin. In cold weather, we tend to produce less blood flow near the surface of the skin as the blood is rerouted to warm more important parts of our bodies (it is why our fingers and noses get so cold). Some people enjoy jogging in the snow, but keep in mind that this may have an affect on an accurate heart rate reading from your Apple Watch.

Avoid Irregular Motion

Apple Watch gets a better reading when you've calibrated it by walking or running for 20 minutes. It tracks the rhythm of your movement and adjusts its data accordingly.

However, irregular movement, like playing tennis or boxing, will confuse the sensor and reduce its accuracy. So, for such workouts that have you swinging your arms wildly, be aware that your heart rate reading may not be as accurate as you would like.

Troubleshooting

If, for some reason, the heart rate monitor on your Apple Watch stops working, you may need to restart or reset the device.

Apple Watch Erase All Settings

  1. Press and hold the Side button until the power off slider bar appears and slide it to turn off Apple Watch.
  2. Press and hold the Side button again until the Apple Watch logo appears.

If that does not work, try resetting your Apple Watch.

  1. On Apple Watch, open the Settings app and tap General.
  2. Tap Reset. Then tap "Erase All Content and Settings."
  3. Re-pair Apple Watch with your iPhone.

Although it is not an exact science, the heart rate monitor on Apple Watch is a useful way of tracking your activities and getting a better estimate on how many calories you burn. Following the tips above will improve accuracy of the light-absorbing sensors.

Related Roundup: Apple Watch 11
Buyer's Guide: Apple Watch (Buy Now)

Top Rated Comments

Iconoclysm Avatar
135 months ago
That gap/no gap method is incorrect as this differs greatly depending on the shape of your wrist. If the watch is snug, it's snug, if it can't move around...it can't move around. For some people, that will mean there is a gap in the band. The watch itself is raised up, if you have a slimmer wrist, it is absolutely impossible to remove that gap.
Score: 6 Votes (Like | Disagree)
0098386 Avatar
135 months ago
Step 1) don't have a sleeve tattoo.
Score: 4 Votes (Like | Disagree)
Zakkates Avatar
135 months ago
The heart rate monitor is pretty much useless when I'm lifting weights (especially HIIT).

When I'm on the treadmill at a steady pace, the Apple Watch most often is spot on with what the machine says my heart rate is.

However, when I'm lifting weights w/ a lot of movement, I can feel my heart rate is at least over 150bpm, but the Apple Watch freaks out and says I have "37bpm" or "87bpm" or can't read. It's very frustrating.

Does hair on the wrist effect it at all?
Score: 1 Votes (Like | Disagree)
nick42983 Avatar
132 months ago
The heart rate monitor is pretty much useless when I'm lifting weights (especially HIIT).

When I'm on the treadmill at a steady pace, the Apple Watch most often is spot on with what the machine says my heart rate is.

However, when I'm lifting weights w/ a lot of movement, I can feel my heart rate is at least over 150bpm, but the Apple Watch freaks out and says I have "37bpm" or "87bpm" or can't read. It's very frustrating.

Does hair on the wrist effect it at all?
I've had the same problems with weightlifing. Sometimes I'll simply exit out of the workout app and go to the HR monitor in glances until it gets the right reading and then go back to the workout app and it will update with the proper measurement. When it's accurate it's great, but I feel that 30%+ of my gym calories burned aren't being measured.
Score: 1 Votes (Like | Disagree)

Popular Stories

Apple Logo Spotlight

Report: Apple to Launch These New Products in 2026

Sunday November 2, 2025 5:34 am PST by
Apple is planning to launch at least 15 new products in 2026, according to Bloomberg's Mark Gurman. Gurman outlined what to expect from Apple in 2026 in the latest edition of his "Power On" newsletter. He said the company is heading "into one of its most pivotal years in recent memory," with the rollout of major new Apple Intelligence features, intense regulatory pressure on the App Store,...
ios 26 1 slide to stop

iOS 26.1 Brings Back 2007 Feature in New Way

Friday October 31, 2025 1:40 pm PDT by
The upcoming iOS 26.1 update includes a small but helpful change for iPhones, and it could prevent you from running late to something important. Specifically, when an alarm goes off in the Clock app, there is a new "slide to stop" control on the screen for turning off the alarm. On previous iOS 26 versions, there is simply a large "stop" button, which could be accidentally tapped. The new ...
Apple Intelligence General Feature 2

New Version of Siri to 'Lean' on Google Gemini

Sunday November 2, 2025 6:06 am PST by
In his "Power On" newsletter, Bloomberg's Mark Gurman today provided an update on the status of Apple Intelligence and the plans for it in 2026. Apple is still planning to roll out its revamped version of Siri around March of next year. The release should be accompanied by the release of a new smart home display product with speaker-base and wall-mount options. A new Apple TV and HomePod...
HomePod mini and Apple TV

New Apple TV and HomePod Mini Likely Launching Soon

Sunday November 2, 2025 5:49 am PST by
A new Apple TV and HomePod mini could launch as soon as this month, Bloomberg's Mark Gurman today suggested. In today's "Power On" newsletter, Gurman said that Apple retail stores are planning an overnight refresh on the evening of November 11, where changes will be made after closing, such as refreshing displays and placing new products for the following day. The timing of the overnight...
Apple Foldable Thumb

iPhone Fold: Launch, Pricing, and What to Expect From Apple's Foldable

Friday October 31, 2025 8:52 am PDT by
Apple is expected to launch a new foldable iPhone next year, based on multiple rumors and credible sources. The long-awaited device has been rumored for years now, but signs increasingly suggest that 2026 could indeed be the year that Apple releases its first foldable device. Below, we've collated an updated set of key details that have been leaked about Apple's foldable iPhone so far. Ove...
M5 MacBook Pro

Waiting for New Macs? Apple Just Shared Bad News

Friday October 31, 2025 7:32 am PDT by
Apple has just given a strong indication that it will not be releasing any additional new Macs for the remainder of the year. Apple's CFO Kevan Parekh dropped the hint during the company's earnings call on Thursday:On Mac, keep in mind, we expect to face a very difficult compare against the M4 MacBook Pro, Mac mini, and iMac launches in the year-ago quarter.Parekh essentially gave a heads up ...
iOS 26

Apple Releases iOS 26.1 With Liquid Glass Toggle, Slide to Stop Alarm, New Apple Intelligence Languages and More

Monday November 3, 2025 1:11 pm PST by
Apple today released iOS 26.1, the first major update to the iOS 26 operating system that came out in September, iOS 26.1 comes over a month after iOS 26 launched. ‌iOS 26‌.1 is compatible with the ‌iPhone‌ 11 series and later, as well as the second-generation ‌iPhone‌ SE. The new software can be downloaded on eligible iPhones over-the-air by going to Settings > General >...
iOS 26

6 New Things Your iPhone Can Do in iOS 26.1

Wednesday October 29, 2025 4:22 am PDT by
Apple is about to drop iOS 26.1, the first major point release since iOS 26 was rolled out in September, and there are at least six notable changes and improvements to look forward to. We've rounded them up below. Apple has already provided developers and public beta testers with the release candidate version of iOS 26.1, which means Apple will likely roll out the update to all compatible...
Early Black Friday Deals 2

The Best Early Black Friday Apple Deals

Sunday November 2, 2025 10:04 am PST by
We're officially in the month of Black Friday, which will take place on Friday, November 28 in 2025. As always, this will be the best time of the year to shop for great deals, including popular Apple products like AirPods, iPad, Apple Watch, and more. In this article, the majority of the discounts will be found on Amazon. Note: MacRumors is an affiliate partner with some of these vendors. When ...