Sleep Calculator: How Much Sleep Do You Really Need Each Night?

But how do you know if the amount of sleep you’re getting each night is sufficient? Experts say that answer depends on several factors, including your age, stage of development, genetics, and your environment.

The below recommendations from the American Academy of Sleep Medicine outline the ideal amount of sleep a person needs each night depending on their each age:

• Infants 4 to 12 months: 12 to 16 hours of sleep per 24 hours (including naps)
• Children 1 to 2 years: 11 to 14 hours of sleep per 24 hours (including naps)
• Children 3 to 5 years: 10 to 13 hours of sleep per 24 hours (including naps)
• Children 6 to 12 years: 9 to 12 hours of sleep per 24 hours
• Teenagers 13 to 18 years: 8 to 10 hours of sleep per 24 hours
• Adults: 7 or more hours of sleep per night

Ideally, you’re able to sleep according to your circadian rhythm, your body’s natural internal clock. “Your circadian rhythm influences when your body feels sleepy or alert, so it’s what makes us feel sleepy at night,” Dr. Lu says. “When you’re able to make sure your sleep patterns align with your body's natural circadian rhythm, you can experience a more restorative sleep.”

The guidelines from the American Academy of Sleep Medicine suggest that seven or more hours of sleep each night is sufficient for adults. But how do you know if seven hours is your sweet spot or if you need closer to nine to function optimally the next day?

“If you wake up before your alarm goes off in the morning, and you’re feeling refreshed, that’s a good sign your body got the right amount of restorative sleep the night before, and you’ve found what works best for you,” Lu says. “But, if you’re waking up feeling groggy and sluggish, that might be a sign to expand your sleep opportunity.”

It can also help to wear sleep monitor tools like smartwatches and rings that can identify if you’re waking up throughout the night and experiencing sleep disturbances, Lu says. 

“Sleep is important for mental function, including alertness, memory consolidation, and mood regulation,” says Phyllis C. Zee, MD, PhD, director of the sleep disorders center for circadian and sleep medicine and chief of sleep medicine in the department of neurology at Northwestern University Feinberg School of Medicine in Chicago.

Try these tips for better sleep hygiene to help you go to sleep at your determined bedtime:

• Adhere to the same wake and sleep schedule every day, even on the weekends. “Establishing and maintaining a consistent sleep schedule is a key part of waking up feeling refreshed,” Lu says.
• Keep the room you snooze in on the cool side. A temperature in the low to mid 60s F is ideal.

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• Avoid alcohol. “It might seem like you are able to fall asleep easily with alcohol, but later in the night, alcohol has a stimulating effect, which in turn can cause you to wake up earlier,” Lu says. “Alcohol also decreases the amount of deep, restorative sleep that you get, causing you to feel more tired and less refreshed in the morning.”
• Manage mental health conditions. Depression and anxiety can cause changes to sleep, sometimes leading to sleeping too much or too little.

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   Talk to your doctor about treatment options for these conditions, which can help improve sleep.
• Power down electronics at least an hour before bed. “Things like light signal to our body that it’s time to be awake, so putting phones down and turning off nearby TVs and lights can help make falling asleep easier,” Lu says.
• Stick to healthy sleep routines that promote relaxation before bed, such as a warm bath or quiet reading before you snuggle in.

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• Sleep in a dark room. Light stimulates the brain, so Lu suggests using blackout curtains.
• Store your devices outside of the bedroom. Use an alarm clock rather than your phone to wake you up in the morning.

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The Takeaway 

• Sleep is key to a healthy life and promotes weight maintenance, heart health, brain function, and a healthy immune system, among other benefits.
• The recommendations for sleep by age can help determine how much sleep you should aim for, but pay attention to how your body feels the next day as everyone’s needs are a little different.
• If you’re struggling to get to sleep at the appropriate bedtime each night, adopt bedtime techniques for better sleep, such as sticking to a routine and schedule, powering down electronics at least an hour before bed, and setting your bedroom up as a cool, dark retreat.

Additional reporting by Carmen Chai and Moira Lawler.