Many first-gen devices have quirks. Users have reported that the watch over reported calories burned. Rebooting the device could fix the problem according to the team at the Pixel watch. It is an apt reminder that the metric of calories burned isn't a reliable one.

The bug appears to have affected how a user's metabolism was calculated. Basal metabolism rate is the number of calories burned per day. Factors include age, weight, sex, and height. The wrong data will lead to the wrong calories burned. The incorrect user data was fixed when the device was brought back to life.

It is annoying, but it is not that serious. You shouldn't trust any device to give you accurate calories burned.

Wearable devices should not give you accurate calories burned.

Wearable makers don't use the same formula to determine how many calories you burn. They use proprietary methods that take into account factors like heart rate. These devices have multiple sport profiles for tracking activity due to the fact that different workouts will affect calories burned and muscle groups. While running and cycling are both great for cardiovascular activity, you burn more calories while running because you use more muscles.

Dozens of other factors are not accounted for by the watch. Polycystic ovary syndrome is a condition I have. The people with this condition burn 400 fewer calories a day than the people who don't. It's not possible to tick a box on my watch. I don't know how much muscle mass I have, my fitness level, the drugs I take, or the effects of my food on my body.

Woman with hand in pocket wearing Pixel Watch
The calorie bug isn’t that serious because you shouldn’t be putting a lot of trust into wearable calorie metrics to begin with.

A lot of people won't get an accurate number even if they log their exercise and food. A heads-up that something isn't quite right or a broad view of your long-term progress are only some of the things that can be seen from the calories burned. Out of seven trackers tested, none delivered metrics that were within an acceptable range. The most accurate had an error rate of over 25%. It had an error rate of 93 percent.

I don't evaluate how accurate a device's calories burn is because of this. I can't Not in a good way. Check to see if the metrics they get, including calories burned, are consistent.

I used the Apple Watch Ultra and the Runkeeper app to run three 30-minute runs on the same route, at the same speed. The results can be seen in the table.

All of them are in the same place. I don't know which one is the right number, but they're all delivering consistent results Which they are, right? If I wanted, I could use the watch to find out if I am in a deficit or surplus based on my goals. If two devices are within 1,000 steps and 500Kcals, you won't get a different experience.

It would be a problem if the watch gave me three different burn numbers for the same activities. I would dig a little deeper. A walk that was off by 11,000 steps and six miles was recorded by the watch when I was reviewing it. Sometimes it delivered results that were close to reality. It's a red flag.

It would be great to have a device that is accurate. No matter what an executive says at a launch event, it is impossible. Wearables are supposed to help you determine your baseline so you can see your progress over time. Zeroing in on a single metric is not good for the forest.