How does your Apple Watch know how many calories you consume (and is this correct)?

After your run, your Apple Watch tells you exactly how much energy you’ve used down to the calorie. The big question is: how does the watch do this? And perhaps more importantly: is the calculation correct?

This is how an Apple Watch counts calories

To get straight to the point: no, your Apple Watch does not know exactly how many calories you have consumed. However, the watch does make a very accurate estimate. He looks at your metabolism, or the energy consumption. You have an important part in that. A good estimate starts with good data.

If you use an Apple Watch, you need to tell us about your age, weight and height during setup. This information is very important, because it forms the basis for all measurements.

Then it is the turn of the smartwatch from Apple. An Apple Watch is packed with technological gadgets, such as sensors, to map exactly how many calories you consume. For example, the accelerator motor knows whether you are walking or jogging. Your heart rate betrays how intensively you are moving.

But, of course, the Apple Watch doesn’t know everything. That is why it is possible to start certain activities (workouts) manually. In this way, the smartwatch can keep track of exactly how intensive your rowing trip, dance session or Pilates class is.

The last step in calorie counting is mostly software related. Apple uses all kinds of smart algorithms to analyze the information. He makes a distinction between your resting metabolism and your energy expenditure when you exercise. Because even if you don’t exercise, you burn calories.

The watch then makes a fairly accurate estimate of how much energy you have actually used.

How to make your Apple Watch a better dietitian

Now that we know how an Apple Watch measures calories, there is one more question on the table: is the calculation correct? Yes, broadly speaking. Stanford University conducted research into the accuracy of the Apple Watch in 2017.

An important conclusion was that the Apple watch obtained the most accurate statistics and informed users better about their energy consumption than competitors, such as a smart watch from Samsung†

However, it is (and remains) an estimate. After all, it is almost impossible for an Apple Watch to measure exactly how much energy you use. You simply need a more controlled environment for that. For really detailed results you have to attend a survey.

That is of course not easy. There are some tips to fine-tune the calorie consumption. Below you can read 5 tips:

1. Are your details still correct?

As mentioned, an Apple Watch initially calculates your calorie consumption based on your personal data. It is therefore important that this information is (still) correct. Check this by grabbing your iPhone and opening the Health app. Then tap ‘Data’ and go to ‘Body Measurements’.

2. Add workouts

Also important: let your Apple Watch know what kind of sport you are going to do. After all, there is quite a difference in calories burned between rowing for half an hour or walking for thirty minutes.

You do this by starting the Workout app on your Apple Watch and then using the Digital Crown (the dial) to go to the sport you want to do.

3. Set wear detection

It is also useful to enable wear detection. As a result, your Apple smartwatch is not only better able to count calories, but you can also use ‘Fall detection’, for example. This sends out an emergency message the moment you have made a nasty fall and are not able to call for help yourself.

You enable Wear Detection via the Apple Watch app on your iPhone. Go to the ‘My Watch’ tab and tap ‘Passcode’. You can then turn on Wear Detection at the bottom.

4. Wear it correctly

An Apple Watch should not be too loose, but certainly not too tight around the wrist. The watch’s sensors need some breathing room to do their job. Therefore, make sure that the strap is precisely adjusted to your wrist.

5. Start with a clean slate

Finally, you can still calibrate the Apple Watch. This makes the measurements even more accurate. This option is particularly useful if your watch regularly releases incorrect statistics, for example if you actually ran for 30 minutes, but your smartwatch turns it into 20 minutes.

Calibrating an Apple Watch takes a little more time and in the article below we explain exactly how it works.

Read more: How to calibrate an Apple Watch

More Helpful Apple Watch Tips:

• How does your Apple Watch know how many calories you consume (and is this correct)?

• Control Apple Watch with one hand – that’s how it works with AssistiveTouch

• Does your Apple Watch have 4G? That’s how you find out

• Tip: This is how you set a silent alarm on your Apple Watch

• Spotify can now play music offline on the Apple Watch: this is how it works