Sleep Performance
How well last night’s sleep met your need, from 0 to 100%.
- Poor0-69%
- Sufficient70-84%
- Optimal85-100%
What goes in
- Hours asleep
- Your main sleep against your sleep need. Naps are not counted here.
- Sleep efficiency
- Time asleep as a share of time in bed.
- Restorative sleep
- Deep and REM sleep as a share of time asleep.
- Sleep consistency
- Your Sleep Regularity over the last 7 days.
Your sleep need is the upper quartile of your last 28 nights, at least 8 hours (9 under 18) and at most 9.5. Until you have 7 nights, it is 8 hours.
How it is weighted
- Hours vs. need, 50%
- Full marks at 100% of your need.
- Efficiency, 20%
- Scored as the percentage itself.
- Restorative, 20%
- Full marks when deep plus REM reach 50% of your sleep and deep alone reaches 13%. Less deep sleep scales this part down, to half at none.
- Consistency, 10%
- Scored as the consistency percentage.
What the bands mean
- 85-100%
- Optimal
- 70-84%
- Sufficient
- 0-69%
- Poor
The key statistics use their own marks for optimal and sufficient: hours vs. needed 85% and 70%, efficiency 85% and 75%, restorative 40% and 30%, consistency 80% and 70%.
Limits
Sleep Performance scores the main sleep only, once Fitbit has processed it. A night without deep and REM totals scores its restorative part as zero, so it reads lower. Without a consistency reading, that part counts as 50%. Sleep stages come from a wrist sensor and are an estimate.