How does Applewatch calculate the distance ?

[Bosechris]

Hello.

A friends bought a connected bracelet : the Fitbit charge 3.
Sometimes the bracelet add steps when he doesn’t walk.
For this bracelet, moving the hand (washing plates, cookong, ...) is like walking.
Is it the same with the applewatch ?
Is the same with my iPhone X, sometimes I don’t walk but my phone says that I walk.

 

[bruinsrme]

I am sure it uses on board accelerometers and some form of successive approximation with corrections from sources such as gpss and cell towers.

 

[TheMacApple]

I had Fitbit and thought it was better for steps. But, Apple Watch has so much to offer, I don’t care!
The Fitbit would show zero steps when I wake up. Hint hint Apple, it would automatically go to sleep mode when I went to sleep, it knew when I was crashing on the couch watching tv,
Anyway I guess I toss in the sleep cause now I wake up with~100 steps. And nope, checked video and I don’t sleep walk

 

[user1234]

I’m not sure about the step count, but when doing a workout with GPS it’s very accurate. I have tested it against my Garmin E-trex Touch and they are very close. The Garmin does have a better receiver, so I trust it more, but the watch is accurate enough in my opinion.