Sleep
How much of the sleep you needed you actually got.
What it is
Your Sleep score is how much of the sleep you needed you actually got last night, tempered by how efficient and well-structured that sleep was.
How we calculate it
We reprocess the raw sleep stages your watch records (deep, REM, light, awake) rather than using its own figure. Against that we set your personal Sleep Need, which rises a little after a hard training day and when you have been carrying sleep debt across recent nights.
A short nap or a partial capture is not counted as a night, scoring a fragment as a full night would be a wrong number.
Sources
The published research and guidelines this number leans on.
- National Sleep Foundation's sleep time duration recommendations: methodology and results summaryHirshkowitz M et al. (2015) · Sleep Health 1(1):40-43
- Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research SocietyWatson NF et al. (2015) · Sleep 38(6):843-844
- National Sleep Foundation's sleep quality recommendations: first reportOhayon M et al. (2017) · Sleep Health 3(1):6-19
- The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivationVan Dongen HP et al. (2003) · Sleep 26(2):117-126
Last updated 27 August 2026.