Charge 5 is not tracking my sleep times accurately

[kiral9]

Does anyone know how the sleep stages are calculated? Or have any insight to this?

I woke up at 5 am and looked at the app. It said I had 6 hours of sleep and 1.5 hours of deep sleep. I went back to sleep for two hours, checked the app and it said I had 8 hours of sleep and 47 minutes of deep sleep. How did it go down ?

Moderator Edit: Clarified subject

[MarreFitbit]

Hi there, @kiral9. Welcome to the Fitbit Community Forums. Thanks for the details provided in your post about the inconvenience with your Charge 5. I'll be glad to help you!

As a first approached, I'd recommend to sync your Inspire 3 to the app after waking up. This will help to make sure that all your data is sync properly. 

Also, note that your time asleep is calculated by subtracting your time spent awake and restless from your overall tracked sleep time. For example, if you slept 8 hours but woke up 2 times for 15 minutes each, your time asleep would be 7 hr 30 min.

Additionally, keep in mind when your body is completely at rest and you haven’t moved for about an hour, your Fitbit device records that you’re asleep. For more information, see How do I track my sleep with my Fitbit device?

To learn more about your time asleep in sleep stages, see What should I know about Fitbit sleep stages?

[Kdbrou]

My charge 5 tends to underreport my sleep. For the past 2 days, it hasn’t recorded any sleep. Since a recent Apple software update earlier this week, it records my steps, but there is no hourly breakdown.  Wondering if all the issues are related