As we know, sleep is always an important indicator of health and well-being. We spend about 30 percent of lives in sleep, and the state of sleep health is always an essential question throughout our lives. Some people sleep 5 hours, and they are full of energy again, while others still feel drowsy for just 5 hours sleeping. Why? Is 5 hours of sleep enough? Here we’ll show you all the information about sleep time.
- How Much Sleep Do We Need Each Day? 5 hours or 10 hours?
- How Do I Know How Much Sleep I Need?
- What Happens If You Don’t Have Sufficient Sleep?
- Am I Getting Enough Sleep?
- Are You Sleeping Too Little or Too Much?
Let’s dive right in.
How Much Sleep Do We Need Each Day?
Generally speaking, many factors can affect sleeping, such as body health, mental status, recent physical exertion and work intensity, age, and so on. Some people just need less sleep than others, while some people always sleep more than 10 hours.
So how much sleep do we need? Commonly, adults need 7 to 9 hours sleep per night. And around 7 to 7.5 hours of actual sleep appears to be optimal for most people.

NSF’s Recommendations For Sleep Time
The NSF (National Sleep Foundation) is an organization that is fully engaged in improving human health and well-being through sleep education and research. By years of research and review, NSF experts have provided scientifically rigorous recommendations which represent the best guidance for sleep time and health. Let’s have a look.
AGE | RECOMMENDED AMOUNT OF SLEEP |
Newborns (0-3 months) | 14 to 17 hours |
Infants (4-11 months) | 12 to 15 hours |
Toddlers (1-2 years) | 11 to 14 hours |
Preschoolers (3-5 years) | 10 to 13 hours |
School age children(6-13 years) | 9 to 11 hours |
Teenagers (14-17 years) | 8 to 10 hours |
Younger adults (18-25 years) | 7 to 9 hours |
Adults (26-64 years) | 7 to 9 hours |
Older adults (65+ years) | 7 to 8 hours |
- How much sleep does a baby need? Infants sleep up to 17 hours each day. By age two, the required amount of sleep decreases to 14 hours. During this period, infants can sleep at any time, not just during the night. Till six years old, a child get most of his/her sleep during the night.
- How much sleep does a teenager need? As children, they are active and energetic, so they also require less sleep. By the time they reach adolescence, about 9 hours are necessary on average.
- How much sleep does an adult need? We might have some mistakes for adults sleep time. You may hear that some people just sleep as few as 5 hours, while others may need as many as 10 hours. So which one is OK? And what is the truth? From the NSF recommendations, for most adults, 7 to 9 hours per night is the best amount of sleep. The 5 hours or 10 hours is for individuals, not a standard for most people. So please always keep in mind that you are an average man and you need about 7 to 9 sleep per night.
- How much sleep does an older adult need? Sometimes we may hear that we need less sleep when we get older, Is it true? No. NSF’s research have revealed that older adults actually sleep similar amount of time as younger, as much as 7 to 8 hours. The truth is that when we grow older, the neurons responsible for controlling and regulating our sleep patterns slowly die off. This causes older adults to wake up easily, and even to suffer from insomnia in worst case.
How Do I Know How Much Sleep I Need?
Though the required sleep ranges from 5 to 10 hours for adults, you shouldn’t assume that you are at one end of the spectrum. If you are sleepy and drowsy in the day, even during some important events, then in all probability you haven’t had enough sleep in the previous night. We often have a nap in early afternoon – it is called siesta time. But if you fall asleep consistently, it is likely to alarm that you haven’t had enough sleep at night.
Gallup had posted an article which shown one in four has “sleep problem” in older American. So if you are an American, we recommend you read this report. It shown that only 32% American over 50 years old had a good night’s sleep, while 56% got 6 to 8 hours per night, and even 21% said they got fewer than 6 hours per night. The U.S. Department of Health and Human Services also reports that poor sleep health becomes a common problem with 25 percent of U.S. adults, and “The odds of being a short sleeper (defined as someone who sleeps less than 6 hours a night) in the United States have increased significantly over the past 30 years”.
What Happens If You Don’t Have Sufficient Sleep?
Most people have the experience that if you do not sleep for one or two nights your body will to be weak and feeble and your spirit can not be focused on anything during work or study. Insufficient sleep can vastly affect you, anytime anywhere.
Because unlike other things in life, sleep time is not something that is routinely changed. We call this biological clock. And you should arrange your things according to your biological clock. You can’t decrease even a little amount of sleep just to fit your schedule. If you try to, it will affect your judgment and reaction, even if you have not consciously realized it yet.
When we miss sleep, we always think we can make it up in the next few days, such as having a lie-in on Sunday. Then is that true? According to the scientific research, no matter sleeping any hour later, only one third to one half of lost sleep is recovered. That is to say, sleep deficit can not be cured completely. The whole sleep process can be divided into three stages, light sleep, deep sleep and REM sleep. The lost deep sleep can be recovered, but REM sleep can only be recovered about a half. And the light sleep is lost permanently.

Recent medical reports have shown that both short sleepers and long sleepers have higher mortality rates than people with the standard 8 hours sleep. Less sleep is also in connection with higher rates of depression, weight gain, acne, as well as weaker immune system and poorer memory function. If you are a lady, the acne is not what you want definitely. For healthy people, sleep deprivation will negatively affects their cognitive skills.
Older adults are prone to suffer from insomnia. Some experts consider insomnia is along with aging, and the medical problems and other careless treatments in the elderly people may also cause the insomnia to be common in seniors.
Am I Getting Enough Sleep?
Do you know how much sleep you are getting? Mostly not. Maybe you still remember the clock you got to bed yesterday and even the day before yesterday, but unfortunately, you are notoriously inaccurate at estimating how much you slept, and in general people always overestimate their sleep time.
The best way to figure out whether you sleep sufficiently is to mark down the time when you go to bed and when you wake up. You can assume it takes about 15 to 20 minutes to fall asleep, if you don’t have trouble in falling asleep. So add 20 minutes to the time you go to bed, and subtract from the time you wake up, that is the time you real sleep. Now please check if it is within the recommended range of 7-9 hours.
If yes, but you don’t feel rested yet, below are some signs that indicate you may get less or more sleep.
Signs For Getting Too Much Sleep
- It takes you more than 1 hour to fall asleep
- You regularly wake up before your alarm, but still feel rested in the day
- You feel depressed, and even be hypersomnia
- You have low energy in the day
- You gain weight for lack of activity
Signs For Getting Less Sleep
- You wake up during the night from nightmare, stress or sleep disorder
- You sleep over your normal wakeup time
- You are moody and easily irritable
- You gain weight
- You have drowsiness even in important occasions
- You forget things more often recently, and working performance became poor

Are You Sleeping Too Little or Too Much?
How do you know if you sleep enough or not? Realistically, you can not be aware of this till it impacts your daytime life, such as working performance, making decision, etc.
Usually there is no particular reason to worry about sleeping less or more. You might think sleeping too much is a problem, that wastes your time, and your might also heard that hypersomnia is recognized as a clinical condition. But in fact most of long sleepers can not be confirmed as hypersomniac, and for hypersomnia doctors can nearly do nothing except prescribe some stimulants. So it is not worth worrying about.
On the other hand, your family or your team members will also you in life. If you sleep too much, they will wake you up, and if you sleep less, they will also notify you to go to bed early. So please take it easy and all you should do is paying more attention to schedules and making your sleep time regularly.