How accurately does Apple Watch track calories burned?

The Apple Watch doesn’t use magic to calculate the calories you burn during a workout. Instead, it relies on highly advanced, ever-evolving algorithms to provide accurate estimates. How accurate? It depends, plus how you use your watch also matters. Let’s dive into the watch’s track record of how effectively it tracks calorie output. We also included a few optimization tips.

How accurate is ‘highly accurate,’ according to Apple and other studies?

If you’re looking for a percentage or range, you won’t find it from Apple. The company hasn’t made any official claims regarding the accuracy of its calorie burn tracker. But, compared to competitors, our testing has confirmed that the Apple Watch is shoulder-to-shoulder with the rest of the top-tier fitness trackers, such as the Samsung Galaxy Watch 6.

Some users have taken the testing into their own hands, such as this 12-week study. Although not scientifically backed, the writer kept meticulous records of his caloric intake and his weight change. After three months, he found that the weight predicted by the watch’s data and his actual weight differed by only 0.4 pounds. Thus, this single-subject study concluded that the accuracy of the Apple Watch is “really good.”

Another Apple Watch fan tested its accuracy by comparing his weight with the calorie tracker’s data. Ken Lynch of The Wearable Guy found that the Apple Watch overestimated his burned calories by 10% to 25%. Again, these aren’t scientific studies, but they do support other users’ claims that the calorie burn counter may tend to be overestimated.

How to optimize Apple Watch to accurately track calories burned

Here are four ways we’ve found can help you achieve a close to objective “accurate” reading. If you follow these tips, it should give you highly accurate estimates of your calories burned.

1. Accurately input (and update) your stats

During the initial set-up, the Apple Watch’s Fitness app asks for several data points: age, gender, weight, and height. This is the first opportunity to optimize the accuracy of the calorie tracker. Take the time to measure your current weight and height as accurately as possible. (If these numbers change, don’t forget to update them on the Health Details page in the Watch app.)

2. Calibrate your Apple Watch

You should also calibrate your Apple Watch frequently. Performing the calibration is quick and easy, and it can help the algorithm build your fitness profile. Older Apple Watch models need to be calibrated through the Watch app on your paired iPhone, but all the latest models can be calibrated directly on the watch itself.

3. Position your watch so Wrist Detection can do its magic

The next big boost to the calorie tracker’s accuracy is Wrist Detection. The Apple Watch can monitor your heart rate but only if you give the sensors permission within the Watch app on your connected iPhone. And once you turn it on, the Wrist Detection sensor only functions properly when it has continuous contact with your wrist.

Make sure your watchband is well-fitted and even a little snug. You can do some jumping jacks or shake your arm to test if it’s tight enough. If you feel the watch wiggling or lifting off your wrist, it’s likely too loose to give an accurate heart rate reading.

4. Utilize the Apple Watch’s Workout App

Finally, select your workout on the Workout App.

If your specific activity isn’t on there, look for the most similar option. For example, if you’re walking in the park and decide to take a trail that rises over rocky terrain, switch your activity from “walking” to “hiking,” even if it’s just for a jaunt.

This is where all that data matters the most. The Apple Watch adjusts its sensors and readings according to the workout you select. For instance, the accelerometer records swimming data differently from walking data, as swimming takes more energy to travel the same distance.

Is Apple Watch accurately tracking calories burned?

It might not be perfect, but it’s pretty darn close.

It’s important to keep in mind that no matter how “smart” your wearable tech is, calorie estimates will always have a margin of error. The Apple Watch possesses a highly accurate calorie burn tracker as long as you provide it with accurate data. Follow our tips above for optimizing the Apple Watch’s accuracy, and you can confidently rely on its data to guide your health goals.