How is the breathing rate during the sleep calculated by Fitbit?

[Angelinalien]

How is the breathing rate during the sleep calculated by Fitbit?  
Is breathing IN =1 and breathing OUT= 2 or is breathing IN and OUT=1? 
I would like to know to be able to compare with other scientific topics around this subject.

Thank you in advance for any information you can share on this topic.

Moderator edit: clarified subject.

[ManuFitbit]

Hi @Angelinalien. A warm welcome to the community forums.

Thank you for sharing the query regarding breath. 

Breathing Rate or Respiratory Rate is a measurement of your average breaths per minute at night. The Fitbit smartwatch uses body sensors to record the average number of breaths you take per minute while you’re asleep and provides a summary value when you’re awake. This allows you to better monitor your vitals and general health throughout the day.

In order to see more information, please visit: How do I track breathing rate in the Fitbit app?

Also, take a look at this help article: What should I know about health metrics in the Fitbit app?

[LZeeW]

Hello @Angelinalien and welcome to the Community.  I moved your post to one of the developer forums.  I hope it helps you get the information you need.

[Gordon-C]

Hi @Angelinalien 

We don't share a lot of information on how metrics are calculated.  However, based on the definition of breathing rate being an average number of breathes taken in a sleep period, one can assume a single complete breath includes the breathing IN & OUT.  

This might be a little more information than you want, the Web API can return 2 metrics for breathing rate.   First, breathing rate a single number representing the average number of breathe taken during the sleep period.  We can also return the breathing rate intraday data which is average number of breathes taken during the sleep period, but categorizing the breathes by sleep stage.