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sleep tips

Sleep Calculator: How Much Sleep Do I Need?


man in white sleepwear sleeps in white bed in the backdrop of a white alarm clock

Quality sleep, which means getting enough of it and staying asleep for an uninterrupted period of time, is as essential to your health as food and water. Not only do you need sleep, you need the right amount of sleep and you need it to be uninterrupted. As a quick example, being in bed asleep for eight hours but waking up three times because you’re hot and sweaty is not the same thing as sleeping for eight hours continuously. In order to understand why, it’s important to learn about your body’s healthy sleep cycles, especially the REM cycle.

What is a sleep cycle? 

Have you ever gotten eight hours of sleep, yet woken up feeling as if you had none? More than likely, you woke up a lot throughout those eight hours. While waking up a few times overnight when you hear the neighbor’s dog barking, use the restroom, or roll into a comfortable position may not seem like a big deal, it wrecks your overall sleep. This is because of your sleep cycle. While you're getting your nightly sleep, your brain goes through various patterns of activity in a predictable cycle.

There are four different stages of sleep; each is important and each is unique. These are Stage 1, Stage 2, and Stage 3 (Deep Sleep), and REM sleep. This cycle doesn’t occur just once. In fact, it repeats itself as you sleep throughout the night. If you’re waking up throughout the night, you may only be entering the first few stages each time and that’s a big problem. The REM cycle is where a lot of important things happen, especially in your brain. Essentially, your brain is “washed clean” during this cycle, helping to improve your cognitive performance and ability to control your emotions. 

You may be wondering how long is a sleep cycle. Your REM cycle first occurs about 90 minutes after falling asleep. If you’re waking up, you're not entering this vital stage. If you get a full night of sleep, you will go through each stage up to five times. 

Think of it this way. You’re going on a road trip, but every time you stop for gas, you start the trip all over again. You’re driving the same 200 miles over and over. You may eventually drive 1,000 miles but you’re never reaching your final destination. This is what it’s like to fall asleep, wake up, and never actually reach the REM cycle.

How to measure the quality of rest 

The question becomes, are you entering all of your needed stages of sleep? To answer that question, it’s important to understand the concept of “sleep satisfaction.” Essentially- how do you feel about your night of sleep last night? A person’s views of what makes sleep satisfying can vary based on a number of different factors, like their current lifestyle and previous experiences with sleep. Six hours of sleep may not feel like nearly enough for most people, but for the nursing mother of a newborn it might seem like a lot. As another example, a person who lies awake for 30 minutes before falling asleep may still be satisfied with their slumber if they sleep soundly through the night once they do drift off and complete their sleep cycle again and again. 

How much sleep do I need?

The answer to this question is actually a little more complicated than one would hope because it depends on several factors, including your age. An infant may need up to 17 hours of sleep each day, but you certainly don’t (and couldn’t, even if you needed to!) Really, you are probably asking: how much sleep do adults need? You may not realize it, but the amount of sleep you get can affect everything from your weight and metabolism to your brain function and mood. That’s why finding the answer to this question is so important.  

Recommended Sleep Guidelines Based on Age

  • Birth to 3 months: 14 to 17 hours
  • 4 to 11 months: 12 to 16 hours
  • 1 to 2 years: 11 to 14 hours
  • 3 to 5 years: 10 to 13 hours
  • 6 to 12 years: 9 to 12 hours
  • Teenage years: 8 to 10 hours
  • Adults up to age 65: 7 to 9 hours
  • Senior citizens 65 years and older: 7 to 8 hours

How to use a sleep cycle calculator

For most adults, their wake-up time is a constant. You need to wake up at a certain time to get your kids ready for school or get to work on time. You may sleep in a bit later on Saturday mornings, but for the most part you wake up at the same time every morning. What time you go to sleep, on the other hand, tends to vary depending on your social life, work schedule, family obligations, whether or not your favorite TV show is on, how captivating your new book is, or simply when you actually feel sleepy. 

If you know what time you have to get up, and you know you need a specific amount of sleep to function at your best, you just need to figure out what time to go to bed. That is what a sleep calculator is! You can find a really handy sleep calculator by clicking on this link. Essentially, bedtimes are based on:

  1. Your wake-up time the next morning
  2. Allowing 15 minutes to fall asleep
  3. Completing at least five 90-minute sleep cycles

How many hours of sleep do adults need? Now that you know the answer to this question, you can get to work making sure you actually achieve it every night. The key to sleeping soundly for seven to eight hours every night is to set yourself up to have a night of sleep you’ll consider a good one. A few small adjustments to your bedroom can result in better sleep and a higher level of sleep satisfaction. Create a sleep oasis with a comfortable, supportive mattress. Keep your room cool, quiet, clean, and uncluttered. Consider installing blackout curtains and a white noise machine to limit distractions. Enacting a bedtime routine with healthy, calming activities, like a warm bath and reading a book, helps too.