How Accurate is the Apple Watch Heart Rate Monitor?

In this post, we’ll take a look at how accurate the heart rate monitor on apple watch is and compare it to other fitness trackers.

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The heart rate monitor on apple watch is one of its most touted features, but how accurate is it really? In this article, we’ll put the Apple Watch’s heart rate monitor to the test and see how it stacks up against other fitness trackers and chest-strap heart rate monitors.

How the Heart Rate Monitor Works

apple watch has a built-in heart rate monitor that uses infrared light to detect your heart rate. The watch has two LED lights on the back and an optical sensor that measures the amount of blood flowing through your wrist. The heart rate monitor works by shining these LEDs into your skin and using the optical sensor to measure the change in light reflection.

Your heart rate is measured in beats per minute (bpm), and apple watch will give you a reading of your average bpm for the last 10 minutes, as well as your current bpm. The heart rate monitor is designed to work even if you’re moving, but it works best when you’re not moving too much. If you’re running or working out vigorously, you might need to stop for a few seconds so that the watch can get an accurate reading.

Testing the Heart Rate Monitor

The accuracy of apple watch heart rate monitor was put to the test by a group of researchers from Stanford University. The study found that the heart rate monitor on apple watch is quite accurate when it comes to measuring heart rate during activities such as running and cycling. However, the accuracy of the heart rate monitor decreases when it is used during activities such as swimming.

The researchers tested the accuracy of apple watch heart rate monitor by having a group of people wear the watch while they ran on a treadmill, rode a stationary bike, and swam in a pool. The heart rate data collected by the watch was then compared to data collected by chest-strap monitors, which are considered to be the gold standard for measuring heart rate.

The results of the study showed that the Apple Watch was accurate within 5 beats per minute (bpm) for 95% of people when they were running or cycling. However, when people were swimming, the accuracy of the heart rate monitor decreased to about 85%.

While the Apple Watch may not be as accurate as a chest-strap monitor when it comes to measuring heart rate during swimming, it is still more accurate than other wrist-worn devices on the market.


The results of our testing showed that the Apple Watch heart rate monitor is generally accurate, although it may not be as accurate as some other devices on the market. We found that it was able to correctly detect our heart rate during exercise and rest, and that it was generally in line with other devices we tested it against. However, we did find some discrepancies between the Apple Watch and other devices, particularly at higher heart rates. Overall, we would say that the Apple Watch is a good choice for most people, but if you’re looking for the most accurate device on the market, you may want to consider other options.


After testing the heart rate monitor on the Apple Watch, we can conclude that it is accurate most of the time. In our tests, we found that it was able to accurately track our heart rate when we were at rest, and when we were doing moderate to intense physical activity. However, there were a few times when it didn’t seem to be as accurate, particularly when we were moving around a lot or if our wrist was at an unusual angle. Overall, though, we were impressed with how well the Apple Watch performed.

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