Sleep stage charts and bar graphs are out of order

[Christobak]

The stages of sleep according to the information in the app are light, deep, then REM. However the charts and graphs organize them as REM, light, then deep. If the purpose of the graph is to visualize the depth and quality of sleep then the charts need to be revised. It doesn't make sense that REM sleep is above light sleep and deep sleep is the lowest and darkest blue. The chart would look different and be more accurate if the sleep stages were rearranged on the y axis.

[RobertoME]

Hello @Christobak, welcome aboard to the Fitbit Community. Yes you are right, but this is the way it works your sleep stages.

Fitbit estimates your sleep stages using a combination of your movement and heart-rate patterns. When you haven’t moved for about an hour, your tracker assumes that you’re asleep. Additional data—such as the length of time your movements are indicative of sleep behavior (such as rolling over, etc.)—help confirm that you’re asleep. While you’re sleeping, your device tracks the beat-to-beat changes in your heart rate, known as heart rate variability (HRV), which fluctuate as you transition between light sleep, deep sleep, and REM sleep stages. When you sync your tracker in the morning, we use your movement and heart rate patterns to estimate your sleep cycles from the previous night. 

In other words according to the quality of your sleep you may see variations on different sleep stages. So if your Sleep graph looks like the following example, your sleep is correct.

Hope this information helps. See you around!