How much deep sleep do you need each night to wake up feeling rested and allow your body and brain to recover?
Deep sleep is an important part of your sleep cycle. During this stage, your body carries out processes that support physical recovery, while your brain also gets time to rest and recover. But the amount of deep sleep you get can vary from night to night and may change as you get older.
So, how much deep sleep do you actually need? There is no single number that applies to everyone. Your age, sleep patterns, and overall health can all affect how much deep sleep you get.
In this guide, we’ll look at how much deep sleep you may need, how it can change with age, why deep sleep matters, and simple habits that may help you get better-quality sleep.
How Much Deep Sleep Do You Need Per Night?
There is no exact amount of deep sleep that every person needs each night.
For most adults, deep sleep makes up roughly 10% to 20% of total sleep, although the amount can vary from person to person and from one night to another. If you sleep for about 7 to 9 hours, that could mean roughly 40 minutes to nearly 2 hours of deep sleep.
What matters isn’t reaching a specific number every night. Your overall sleep duration and quality are also important. The National Sleep Foundation notes that adults generally need around 7 to 9 hours of sleep each night.
Your deep sleep can also change with age. Younger people generally spend more time in deep sleep, while the amount tends to decrease as people get older.
If your sleep tracker shows that you had less deep sleep on one particular night, there is usually no need to panic. Sleep stages naturally vary, and consumer sleep trackers cannot always measure sleep stages as accurately as a clinical sleep study.
The bigger picture is how you feel and function during the day, along with whether you are regularly getting enough sleep.
If you are working on improving your overall health, you may also find our guide on health tips for a vibrant life helpful.
How Much Deep Sleep Do You Need by Age?
The amount of deep sleep you get can change as you grow older. Children generally spend more time in deep sleep than adults, while deep sleep tends to decrease with age.
This is one reason you shouldn’t compare your sleep tracker results with someone else’s and assume that you are getting too little deep sleep.
- Babies and young children: Deep sleep is an important part of early development, and children generally spend a larger portion of their sleep in deeper stages than adults.
- Teenagers: The body and brain are still developing, so teenagers need more total sleep than adults. Their sleep patterns can also differ from those of younger children and adults.
- Adults: Most adults need about 7 to 9 hours of sleep each night, but there is no recommended number of deep-sleep hours that applies equally to every adult.
- Older adults: Deep sleep generally becomes lighter and less frequent with age. This doesn’t necessarily mean an older person is unhealthy, but changes in sleep quality can sometimes be related to medications, health conditions, or other factors.
Instead of focusing only on the amount of deep sleep shown by a smartwatch or sleep-tracking app, pay attention to your overall sleep pattern. Getting enough total sleep and maintaining a consistent sleep routine are important parts of healthy sleep.
If you are regularly waking up tired despite getting enough time in bed, or you have ongoing sleep problems, it may be worth discussing them with a healthcare professional.
Why Is Deep Sleep Important?
Deep sleep is an important stage of your sleep cycle because your body uses this time for several restorative processes.
During deep sleep, your body can focus on physical recovery and other functions that support your health. Deep sleep is also associated with processes involved in learning, memory, and brain functions.
Deep sleep may also support your body as you recover from the physical demands of everyday life. This is particularly relevant if you exercise regularly, because adequate sleep is part of a healthy recovery routine.
However, deep sleep is only one part of a healthy sleep cycle. You also need other stages of sleep, including REM sleep. Rather than trying to maximize one particular stage, the goal is to get enough good-quality sleep overall.
If you consistently get enough time in bed but still feel unusually tired during the day, frequent sleep problems may be worth discussing with a healthcare professional.
Is 1 Hour of Deep Sleep a Night Enough?
One hour of deep sleep may be normal for some people, but it is not a universal target that everyone needs to reach each night.
The amount of deep sleep you get depends on factors such as your age, how long you sleep, and your individual sleep pattern. For example, someone who sleeps for eight hours may naturally get a different amount of deep sleep from someone who sleeps for six hours.
It is also normal for your amount of deep sleep to vary from one night to another. A single night with less deep sleep doesn’t necessarily mean that something is wrong.
Sleep trackers can also make this question more complicated. Smartwatches and other consumer devices estimate sleep stages using signals such as movement and heart rate. They can be useful for noticing general patterns, but they don’t measure sleep stages as precisely as a clinical sleep study.
Instead of worrying about whether you reached exactly one hour, focus on getting enough total sleep and maintaining healthy sleep habits.
If you regularly wake up feeling unrefreshed, experience excessive daytime sleepiness, or have ongoing problems falling or staying asleep, consider speaking with a healthcare professional.
Why Do You Get So Little Deep Sleep?
You may notice that your sleep tracker reports very little deep sleep on some nights. This can happen for several reasons, and one low reading doesn’t necessarily mean that you have a sleep problem.
Your sleep can be affected by your daily routine, environment, age, and overall health. Some factors that may affect sleep quality include:
- An inconsistent sleep schedule: Going to bed and waking up at very different times can make it harder to maintain a regular sleep routine.
- Stress and worry: Feeling stressed or anxious can make it harder to relax and may interfere with your sleep.
- Alcohol and caffeine: Consuming alcohol or caffeine, particularly close to bedtime, can affect sleep quality.
- An uncomfortable sleep environment: Too much noise, light, heat, or an uncomfortable bed can make it harder to sleep well.
- Screen use before bed: Using phones, tablets, or other devices late at night may make it harder to wind down.
- Health conditions or medications: Some health problems and medicines can affect sleep patterns.
It is also important to remember that a smartwatch or phone app may not accurately measure how much deep sleep you get. These devices estimate sleep stages rather than measuring brain activity directly.
If you regularly have difficulty sleeping, wake up repeatedly during the night, or feel very tired during the day despite getting enough time in bed, talk with a healthcare professional. Persistent sleep problems can sometimes be related to an underlying condition that needs attention.
A consistent bedtime routine can be a useful starting point.
How Can You Increase Your Deep Sleep Hours?
You cannot control how much deep sleep you get each night, but healthy sleep habits can help support better-quality sleep.
Instead of trying to force your body to reach a specific number of deep-sleep hours, focus on creating conditions that allow you to sleep well.
- Keep a consistent sleep schedule. Try to go to bed and wake up around the same time each day, including weekends. A regular schedule can help support your body’s natural sleep-wake rhythm.
- Create a comfortable bedroom. Keep your sleeping environment quiet, dark, and comfortable. If your room is too warm, noisy, or bright, making small changes may help you sleep more comfortably.
- Limit caffeine later in the day. Caffeine can remain in your system for several hours, so drinking coffee, energy drinks, or other caffeinated beverages late in the day may interfere with sleep.
- Be mindful of alcohol. Although alcohol may make you feel sleepy at first, it can interfere with normal sleep patterns later in the night.
- Give yourself time to wind down. A relaxing routine before bed can help your body transition from daytime activities to sleep. You might read, take a warm bath, stretch gently, or spend some quiet time away from stimulating activities.
- Stay physically active. Regular physical activity can support healthy sleep, although exercising very close to bedtime may not work well for everyone.
If you are consistently struggling with sleep despite making these changes, consider speaking with a healthcare professional. Persistent sleep difficulties may have an underlying cause that needs to be addressed.
Is Deep Sleep Better Than REM Sleep?
Deep sleep and REM sleep are both important, but they serve different purposes. It is not accurate to say that one is better than the other.
Deep sleep, also called slow-wave sleep, is associated with physical restoration and other processes that support your body’s health. It is also the stage in which it can be more difficult to wake someone.
REM sleep is a different stage of the sleep cycle. During REM sleep, brain activity becomes more similar to wakefulness, and most dreaming occurs. REM sleep is also involved in learning, memory, and emotional processing.
Your body naturally moves through different stages of sleep several times during the night. The amount of time you spend in each stage can vary depending on factors such as your age and how long you sleep.
This is why you generally shouldn’t try to maximize deep sleep at the expense of REM sleep. Healthy sleep involves getting enough overall sleep and allowing your body to move naturally through its different sleep stages.
If a sleep tracker reports that you are getting less deep or REM sleep than expected, look at the pattern over time rather than becoming concerned about a single night’s reading. If you consistently have poor-quality sleep or significant daytime sleepiness, speak with a healthcare professional.
Does Deep Sleep Help Clean Your Brain?
You may have heard that deep sleep helps “clean” your brain. While that phrase is a simple way of describing some research, it doesn’t mean that your brain is literally being washed clean while you sleep.
During sleep, your brain remains active and carries out important processes. Research suggests that sleep is involved in the movement and removal of certain waste products from the brain, with the brain’s fluid systems playing a role in this process.
Deep sleep may be particularly important because some studies have linked slow-wave sleep with changes in the movement of fluid through the brain. However, scientists are still studying exactly how these processes work in humans and how they relate to long-term brain health.
So, instead of thinking about deep sleep as a way to “clean your brain,” it is more accurate to think of sleep as an important period when your brain carries out maintenance and other essential functions.
This is another reason why getting enough sleep matters. Instead of focusing on achieving a specific amount of deep sleep, aim for a regular sleep schedule and enough total sleep for your age.
When Should You Talk to a Healthcare Professional About Your Sleep?
Occasional changes in your sleep are normal. You may have a night with less deep sleep because of stress, a change in your routine, travel, or other temporary factors.
However, persistent sleep problems should not be ignored. Consider talking with a healthcare professional if you regularly:
- Have difficulty falling asleep or staying asleep
- Wake up feeling unrefreshed despite getting enough time in bed
- Feel excessively sleepy during the day
- Snore loudly or wake up gasping or choking
- Wake frequently throughout the night
- Notice that poor sleep is affecting your daily activities
A healthcare professional can help determine whether an underlying sleep problem or another health issue could be contributing to your symptoms.
If you use a smartwatch or sleep-tracking app, you can share your long-term sleep patterns with your healthcare professional, but remember that these devices estimate sleep stages and are not a substitute for a professional sleep evaluation.
The Bottom Line
So, how much deep sleep do you need? There is no single number that everyone needs each night. The amount of deep sleep you get can vary with age, your total sleep time, and your individual sleep pattern.
Instead of focusing too much on the number reported by a sleep tracker, focus on getting enough sleep overall and maintaining habits that support good-quality rest.
A consistent sleep schedule, a comfortable sleep environment, regular physical activity, and a relaxing bedtime routine can all support healthier sleep.
If you regularly wake up feeling tired, have trouble sleeping, or experience excessive daytime sleepiness, consider speaking with a healthcare professional. Good sleep is an important part of taking care of your overall health.
How much deep sleep do you usually get each night? Share your experience in the comments below.
