How much should I sleep a day?  It's a question many are asking — and while you'll often hear that eight hours is the magic number, the actual number of hours of sleep you need varies by age, genetics and how well you sleep at night. 

Sleep by the Numbers 

The average American clocks about six to seven hours of sleep each night, according to a Sleep Number survey.* 

However, studies suggest that regularly getting less than the ideal sleep increases the risk of obesity, heart disease and depression, among others, so aim for a minimum of seven hours. 

A lack of sleep can lead to unwanted side effects: The Centers for Disease Control reports that the risk of health problems like high blood pressure, type 2 diabetes, and obesity rises with less sleep, and the Mayo Clinic states that children don't perform as well on tests with less than eight hours of sleep. 

Think back to a recent good night's sleep — chances are it was somewhere between seven and nine hours per night, which is the sweet spot for most people.

Read on to find out how much sleep you need, and how you can tell if you are getting enough quality sleep. 

Who Needs the Most Sleep? 

Your sleep requirements change over time. The Sleep Foundation identifies nine different age groups and their nightly sleep requirements: 

• Newborns: 14-17 hours 
• Infants: 12-15 hours
• Toddlers: 11-14 hours 
• Preschoolers: 10-13 hours 
• School-aged children: 9-11 hours 
• Teens: 8-10 hours
• Young adults: 7-9 hours
• Adults: 7-9 hours
• Older adults: 7-8 hours 

Of course, these numbers are guidelines only — sleeping an hour more or less than these norms may also be acceptable. Some people need more, while others need less sleep (read more about that: Can 4 Hours of Sleep a Night Be Healthy?) 

How Do You Know If You're Getting Enough Sleep? 

Before stressing over whether you're getting enough sleep for your age and genetics, some telltale signs can help determine if you're rested and getting enough of the quality sleep you need. 

“Ongoing lack of quality sleep can have severe health consequences such as developing heart disease, type 2 diabetes, obesity, depression and anxiety." says W. Christopher Winter, MD, President, Charlottesville Neurology and Sleep Medicine and author of "The Rested Child" and "The Sleep Solution." 

People who don't sleep well or enough can be tired, cranky, irritable, in a bad mood and fatigued during the day, to name just a few signs of too little sleep. 

When you sleep enough, your body will let you know through physical, emotional and health cues. You have more energy, you don't feel sleepy or restless during daytime hours and feel refreshed when you wake most days of the week. Emotionally, you'll have more patience with your partner or kids, you may be in a better mood and have the focus to learn new skills easily. 

This is because, poor sleep has an impact on cognition, alertness and reaction time, “all of which are very important ," says Dr. Peter Polos, MD, PhD, FCCP, FAASM, a sleep medicine specialist and sleep expert for Sleep Number. 

Quality sleep can also help boost your immune system, which means fewer colds and flu, and good working memory and concentration that help with school, work and everyday life. 

Physically, you should be able to achieve your weight loss or exercise goals more easily, including having better muscle movements, so you're able to swing a golf club or walk the dog without tiring. 

Plus, you're likely to enjoy healthier-looking skin, clearer, less puffy eyes and fuller hair. A  2020 Korean study found that even after a few days of sleep deprivation, skin becomes dehydrated and loses elasticity. 

See How Well You're Sleeping 

For insights into your sleeping hours and habits, nothing can beat data. 

You can use a sleep journal, a wearable tracker or an app, for example. With a Sleep Number ^® smart bed, you can easily track your circadian rhythm, average heart rate and breathing rate to keep tabs on your sleep health, plus how well and how long you sleep each night. 

Sleepers who routinely use their Sleep Number^® smart bed technology can get 28 minutes more restful sleep per night — that's up to 170 hours per year!** On nights when you can't get 7-9 hours of sleep, focus on getting the quality sleep you need. 

Get more info on How to Sleep Better. 

Like diet and exercise, quality sleep is essential for optimal wellbeing and performance. Because everyone's sleep needs are different, Sleep Number^® smart beds sense your movements and automatically adjust firmness, comfort and support to keep you both sleeping comfortably. Find your Sleep Number^® setting for your best possible night's sleep. 

*Sleep Number's national sleep study surveyed 1,057 members of GfK's Knowledge Panel consumer online database and data was weighted to the U.S. population ages 18 to 68. A total of 5,134 surveys were completed for the state sleep study survey, approximately 100 in each state and Washington, D.C. The margin of sampling error is +/- 3 percent. 

**Based on average SleepIQ^® data from 8/1/21 – 2/28/22 of sleepers who engaged with their Sleep Number^® setting, SleepIQ^® data and FlexFit™ smart adjustable base. 

ABOUT THE AUTHOR 

Jennifer Nelson is a Florida-based health writer who writes about all things sleep hygiene. She writes for The National Sleep Foundation, Phillips, Tom's Guide, Southern Living, Health, AARP, and others.