How much deep sleep do you need each night?

Key Points

Research suggests adults need about 1.5 to 2 hours of deep sleep each night for optimal health.
The evidence leans toward deep sleep making up 15% to 25% of total sleep time, varying by age.
It seems likely that younger adults (under 30) get around 2 hours, while older adults (over 65) may get less than an hour.

Amount Needed

Most adults aim for 7–9 hours of total sleep nightly, with deep sleep typically accounting for 1.5 to 2 hours. This stage is crucial for physical repair and memory consolidation, so getting enough can help you feel refreshed.

Getting a lot of questions about sleep needs. Most people need 7-8 hours. Most kids need 8-10. Some adults, however, do just fine on 5 hours (consistently). There are also data showing that positive anticipation of next day events improves depth of sleep & shortens sleep need.
— Andrew D. Huberman, Ph.D. (@hubermanlab) January 21, 2025

Age Variations

Deep sleep duration decreases with age. For example, children and teenagers need more, while older adults naturally have less, which might explain why they feel less rested.

Unexpected Detail

It’s interesting that deep sleep often happens early in the night, and napping frequently might reduce your nighttime deep sleep needs, which could affect your sleep strategy.

Survey Note: Exploring Deep Sleep Duration and Its Implications

This note provides a comprehensive examination of how much deep sleep adults need each night, building on the key points and expanding into detailed insights for a thorough understanding. Deep sleep, also known as slow-wave sleep (SWS), is a critical component of the sleep cycle, and its duration varies by age, health, and individual factors. Below, we delve into the recommended duration, age-related variations, and practical implications, supported by recent research and observations as of February 27, 2025.

Recommended Duration for Adults

Research suggests that most adults need approximately 1.5 to 2 hours of deep sleep per night for optimal health and functioning. This aligns with findings from various health sources, which indicate that deep sleep typically constitutes 15% to 25% of total sleep time. For an adult sleeping 7–9 hours nightly, this translates to about 63 to 135 minutes of deep sleep. For instance, Healthline notes that most adults need around 1.5–2 hours, while Sleep Foundation suggests up to 20% of the night, or about 1.4–1.8 hours for 7–9 hours of sleep.

However, there is no definitive consensus on a fixed amount, as individual needs can vary. Medical News Today highlights that the amount of deep sleep relates to overall sleep duration, with 7 or more hours usually providing enough time for deeper states. The Centers for Disease Control and Prevention (CDC) advise adults aged 18–60 to aim for 7 hours, which typically includes sufficient deep sleep (Healthline). This range is supported by Texas Health, which recommends 13 to 23% of sleep time in deep stages, equating to 1 to 1.84 hours for 8 hours of sleep.

Age-Related Variations

Deep sleep duration varies significantly with age, an unexpected detail given its universal importance. Younger adults (under 30) may get around 2 hours of deep sleep each night, as noted by Healthline, while older adults (over 65) may only get 30 minutes to 1 hour, or sometimes none, reflecting a natural decline (Healthline). This reduction is linked to changes in sleep architecture, with older adults spending more time in lighter sleep stages, as per Sleep Foundation.

Children and teenagers need more deep sleep for growth and development, with babies requiring up to 17 hours of total sleep, a significant portion being deep sleep (Yogasleep). WHOOP indicates that children generally get more deep sleep than adults, and teenagers also need more for brain development. As people age, deep sleep decreases at a rate of about 1.7% per decade, with men experiencing steeper declines, especially after 70, spending an average of 5% of sleep time in deep sleep, compared to 15–20% for women of the same age (WHOOP).

Myth: How much sleep you need each night is a matter of personal preference.

Reality: The amount of sleep adults need is universal. Adults everywhere require 7-8 hours a night in order to be mentally limber.https://t.co/3R3Eq0HHSC
— Daniel Pink (@DanielPink) October 29, 2018

Factors Influencing Deep Sleep Duration

Several factors can affect deep sleep duration, adding complexity to the recommendation. For example, recovering from sleep deprivation might increase deep sleep time, while frequent napping may reduce it, as part of the need is fulfilled during the day (Sleep Foundation). Recent sleep patterns, alcohol consumption, and sleep disorders can also impact deep sleep, with age being a major factor (Texas Health).

Health Implications of Insufficient Deep Sleep

Insufficient deep sleep can lead to various health issues, emphasizing its importance. Without enough, individuals may experience fatigue, memory problems, and increased vulnerability to infections, with potential links to chronic conditions like diabetes and heart disease (Medical News Today). Sleep Doctor notes that not getting enough deep sleep can cause learning difficulties and make one susceptible to infection, with long-term risks for health concerns.

Practical Strategies to Ensure Adequate Deep Sleep

Ensuring adequate deep sleep involves addressing factors that impair it, such as inappropriate sleep environments or late eating. Strategies include setting aside more time for sleep to complete multiple cycles, engaging in vigorous exercise early in the day, and using relaxation techniques like warm baths (Medical News Today). Rise Science suggests improving overall sleep hygiene, such as sticking to a regular bedtime routine and exercising, to naturally increase deep sleep.

Age-Specific Deep Sleep Needs

To provide a clearer picture, here’s a table summarizing deep sleep duration by age group, based on the research:

Age Group	Typical Deep Sleep Duration	Percentage of Total Sleep	Notes
Newborns (0–3 months)	Up to 8–10 hours	~50%	Crucial for rapid growth and development (Yogasleep).
Children (1–12 years)	2–3 hours	~25–40%	Supports growth and brain development (WHOOP).
Teenagers (13–18 years)	1.5–2.5 hours	~20–25%	Essential for emotional regulation and puberty changes (Yogasleep).
Young Adults (18–30)	~2 hours	~20%	Less profound than children, fewer awakenings (Yogasleep).
Adults (30–65)	1.5–2 hours	~15–20%	Decreases slowly, stable total sleep time (Sleep Foundation).
Older Adults (65+)	0.5–1 hour or less	~5–15%	Significant decline, more time in light sleep (Healthline).

This table highlights the variability and underscores the need for age-specific considerations in sleep recommendations.

Conclusion

Research suggests that most adults need about 1.5 to 2 hours of deep sleep each night, making up 15% to 25% of their total sleep time. This amount decreases with age, with younger adults needing more and older adults experiencing a natural decline. The evidence leans toward deep sleep being crucial for physical repair, memory consolidation, and overall health, with insufficient amounts linked to various health risks. This comprehensive understanding, drawn from recent health literature, underscores the importance of prioritizing deep sleep for long-term well-being.