sleep calculator
sleep calculator

To get into a good sleep routine, a person can start by assessing how much sleep they need. Then, they can determine when they should sleep and wake up for optimal health.

Experts believe that sleep is as important to human health as food and water. Getting the right amount of sleep can help prevent disease, boost immunity, and improve mental health.

Yet, many of us are not getting enough sleep. The Centers for Disease Control and Prevention (CDC) estimates that about one-third of adults don’t get the sleep they need.

Creating a healthy sleep pattern may require schedule or lifestyle changes. Although it may be challenging at first, the benefits of adequate sleep are worth the effort.

How Much Should You Sleep?

Although there are general guidelines, some people need more sleep than others due to their lifestyle, any health conditions, and their genetic makeup.

The National Sleep Foundation (NSF) recommends that people of different ages get the following amounts of sleep every 24 hours:

  • newborns (0–3 months): 14–17 hours
  • infants (4–11 months): 12–15 hours
  • toddlers (1–2 years): 11–14 hours
  • preschoolers (3–5 years): 10–13 hours
  • school-age children (6–13 years): 9–11 hours
  • teenagers (14–17 years): 8–10 hours
  • younger adults (18–25 years): 7–9 hours
  • adults (26–64 years): 7–9 hours
  • older adults (65 years and above): 7–8 hours

How to Get the Right Amount

The following chart can help a person know when they need to sleep to get 8 hours of sleep a night.

According to the NSF report, on average, it takes people 10-20 minutes to fall asleep. The calculation below assumes that a person needs 15 minutes, but if someone needs longer, they should adjust their bedtime accordingly.

Wake-up timeBedtime (to get 8 hours of sleep):
4:00 a.m.7:45 p.m.
4:30 a.m.8:15 p.m.
5:00 a.m.8:45 p.m.
5:30 a.m.9:15 p.m.
6:00 a.m.9:45 p.m.
6:30 a.m.10:15 p.m.
7:00 a.m.10:45 p.m.
7:30 a.m.11:15 p.m.
8:00 a.m.11:45 p.m.
8:30 a.m.12:15 a.m.

Sleep Cycles

To rest properly, the body must go through several sleep cycles per night, including rapid eye movement (REM) sleep and non-REM sleep.

The stages of sleep include:

  • Stage 1 Non-REM: This lasts only a few minutes. Breathing, heart rate and brain waves begin to slow down.
  • Stage 2 Non-REM: This stage occurs before the body enters deep sleep. Muscles relax more, and body temperature drops.
  • Stage 3 Non-REM: A person needs to reach this stage of deep sleep to feel rested, and it lasts longer in the first half of the night. Breathing and heart rate slow down to their lowest levels.
  • REM Sleep: Within 90 minutes of falling asleep, a person enters REM sleep. The brain becomes overactive, dreams are more frequent, and the arms and legs become temporarily paralyzed.

If the body does not go through these stages several times a night, a person may wake up tired and disoriented.

How to Get Better Sleep

Sometimes all it takes is simple changes in routine to achieve quality sleep. Other times, a person may need sleep before other activities.

Here are some ways to improve the quality and quantity of sleep:

Be Consistent: Going to bed and waking up at the same time every day helps the body develop a rhythm, which makes falling asleep and waking up more comfortable.
Exercise Every Day: Exercise can improve sleep quality and help people with chronic insomnia.
Avoid caffeine and nicotine: Avoid these stimulants later in the day, as both can take several hours or longer to leave the bloodstream, potentially interfering with sleep.
Eliminate Sound and Light: Earplugs, a white noise machine, and room-darkening curtains or window treatments can help. Various white noise machines are available for purchase online.
Turn Off Tvs, Smartphones, and Tablets at Least 2 Hours Before Bed: These devices, which emit blue light, can suppress melatonin, the hormone necessary for sleep.
Try Relaxing Alternatives: Instead of staring at screens, try taking a warm bath, reading a book, or meditating.


Sleep is vital to health – getting a good night’s rest can help people lose weight and prevent certain health conditions.

In order to get the recommended 7-9 hours each night, it is important to sleep at an appropriate time, which may involve rearranging the routine. For many, this can make a big difference.

If a person has tried various recommendations and strategies and fatigue or trouble sleeping persists, they should see a doctor.