Deep Sleep (N3)
Stage 3 non-REM sleep duration in minutes or % of total sleep
Sleep ArchitectureCategory
About 15-20% of total sleepReference
No clinical target; declines with ageSourced reference
Why Deep Sleep (N3) matters
Most restorative sleep stage. Essential for physical recovery, immune function, and growth hormone release. Declines with age.
Reference Range
About 15-20% of total sleep
Sourced reference
No clinical target; declines with age
Targets by source
Each position below is attributed and linked to the document that states it. Several are population percentiles or averages rather than targets; the note says which. How we verify ranges.
- About 15-20% of the nightOura Ring sleep-stage guide (device vendor)Oura sells the ring that reports these stages and estimates them from heart rate, movement and temperature, not brain activity. A typical average, not a clinical target. Deep sleep declines with age.
Devices that measure this
Devices in our comparisons whose published specs list this metric:
Track Your Sleep Architecture
Monitor Deep Sleep (N3) with wearables and health tracking devices
Health Disclaimer
This information is for educational purposes only. Consult a healthcare provider for personalized health recommendations.
Last reviewed Sep 23, 2026 · First published Oct 1, 2025