There are many reasons why people don’t get enough sleep. Busy schedules, social obligations, and electronic devices can make it challenging to prioritize and make time for sleeping. Many people set an alarm to get an early start on the day, but forget that setting a bedtime is just as important.
A sleep calculator can help you stay on track with your sleep schedule. You can use it to learn more about the recommended amount of sleep you should be getting and the optimal times for going to sleep and waking up. Understanding how sleep works and how much sleep you need can help you improve your sleep habits and stay healthy.
Sleep Cycle Calculator
A sleep calculator is a formula that you can use to plan for the quantity of sleep you want to get. The only information you need is your wake-up time. Here’s how it works:
- The average sleep cycle is 90 minutes long
- A typical night of sleep includes 5 full sleep cycles
- 90 x 5 = 450 minutes, or 7.5 hours
- Starting at your wake time, work back 7.5 hours to find your bedtime
For example: You need to wake at 6 a.m. to get ready for work. Counting back 7.5 hours, your ideal bedtime is 10:30 p.m. That means lights out, in bed, ready for sleep at that time.This bedtime calculation is a starting point that may need some adjustment, as individual sleep cycles vary in their duration. Try your new bedtime for a week.
The goal is to wake naturally about 5 to 10 minutes ahead of your alarm. If you find yourself waking significantly ahead of your alarm, move your bedtime slightly later. If after a week, you’re still sleeping through to your alarm, you need to shift your bedtime earlier. Do so in 15-minute increments until you’re waking naturally just before your alarm.
Measuring Sleep Quality
A sleep calculator not only helps you reach your ideal sleep quantity, but can also help you improve overall sleep quality. Sleep quality is achieved by sustained rest, with sufficient time spent cycling through each of the four sleep stages to maintain physical and mental health and function. Sleep efficiency is one important measure of sleep quality used by sleep scientists and physicians. Although sleep tracking devices and equipment are available to help measure sleep efficiency, the sleep calculator’s formula provides an easy alternative to using technology. You need only a few basic pieces of information about your night of sleep:
- The total amount of time spent in bed sleeping — or trying to sleep — between bedtime and waking
- How long it takes to fall asleep
- The amount of time spent awake during the night
For example, a person spends a total of 7 hours, or 420 minutes in bed. It took them 25 minutes to fall asleep. They spent another 25 minutes awake throughout the night, a result of three separate periods of wakefulness. Here’s how to calculate their sleep efficiency for this night:
- Total sleep time: 420 minutes
- Minus time to fall asleep: 25 minutes
- Minus total time spent awake: 25 minutes
- Actual time spent sleeping: 370 minutes (6 hours, 10 minutes)
Divide 370 minutes by 420 minutes to get 88%. This number represents their sleep efficiency for that night.In sleep science, a result of 85% or higher is a healthy sleep efficiency and a reasonable goal. A score of 90% is considered a very good sleep efficiency. If your number isn’t quite there yet, don’t be discouraged. With attention to your sleep — and a new bedtime — you’ll see this important number start to rise.
How Much Sleep Do You Need?
The amount of sleep you need depends on multiple factors, such as your age, genetics, and daily levels of exercise. Health authorities like the National Sleep Foundation have general guidelines for all age groups on what is considered sufficient sleep. Sleep guidelines are based on scientific research and expert knowledge.
Age in Years
Recommended hours of sleep per 24 hours
0 to 3 months
14 to 17 hours
4 to 11 months
12 to 15 hours
1 to 2 years
11 to 14 hours
3 to 5 years
10 to 13 hours
6 to 12 years
9 to 11 hours
13 to 18 years
8 to 10 hours
18 to 25 years
7 to 9 hours
26 to 64 years
7 to 9 hours
Over 65 years
7 to 8 hours
How Do You Know If You've Gotten Enough Sleep?
If you’re consistently sleeping within the recommended range of hours for your age, you’re most likely getting enough sleep. Unfortunately, busy schedules and daily stress can make it challenging for people to keep track of their sleep. But there are a number of ways you can monitor your sleep.
- Assess how you feel: How you feel and function throughout the day can be an effective way to gauge whether you’re sleeping enough. When people are not getting enough sleep, they generally feel tired after waking up in the morning or find it more challenging to think clearly and function throughout the day.
- Track your sleep: You can use a sleep diary or sleep-tracking technology to help you stay on top of how much sleep you’re getting. Sleep tracking devices can provide information on your sleep quality and quantity. If you notice sleep disturbances or irregular sleeping, it may be helpful to share your sleep trends with a doctor.
When using a sleep diary to track sleep, consider recording the following information:
- The times you go to sleep and wake up
- How you feel after waking up
- How long it takes you to fall asleep after getting in bed
- How many times you woke up in the middle of sleep and how long you stayed awake
- If you take any naps or feel sleepy during the day
- Your meal times throughout the day
- What you are eating and drinking throughout the day
- Whether you drink, smoke, or take any medications or other substances
Benefits of a Good Night's Sleep
The benefits of sleep cannot be overstated. Sleep is essential for your mental health, physical health, and overall well-being. It affects almost every tissue and system in the body, including the brain, heart, and lungs. And it is key to helping the body develop and grow. Some of the numerous benefits to getting a good night’s rest include:
- Keeping you alert during the day
- Helping with focus, concentration, and performance
- Aiding with learning and processing information
- Enabling the brain to form long-term memories
- Producing hormones that allow the body to grow and repair
- Potentially helping remove toxins from the brain
- Supporting emotional health and well-being
- Lowering blood pressure
How to Ensure You Get Better Quality Sleep
There are many ways to improve your sleep at night. Healthy sleep habits can help make it easier to fall asleep and stay asleep throughout the night. If your sleep still doesn’t improve after adjusting your sleep hygiene, be sure to talk to your health care provider.
- Create a routine: Setting up a consistent bedtime schedule and routine can help make bedtimes easier. Wake up and go to sleep at the same time each day, even on weekends, to help ensure quality sleep. Likewise, a warm bath or shower and relaxation routine could help get you in the mood for sleep.
- Watch your diet: The foods you eat can impact how you sleep. Don’t eat large meals or spicy meals two to three hours before going to bed. If you find that you regularly wake up in the middle of the night to use the bathroom, consider limiting the amount of liquids you drink close to bedtime.
- Get moving: Making exercise a regular habit could make it easier to fall asleep at night. However, working out too close to bedtime may make it harder to fall asleep. Try to avoid exercising three hours before bedtime.
- Regulate caffeine, alcohol, and nicotine intake: Certain substances like caffeine and nicotine can disrupt your sleep. To reduce the risk of sleep disruptions, avoid drinking coffee, caffeinated soft drinks, and energy drinks late in the day. Although some people use alcohol to fall asleep, it too can disrupt sleep disturbances and cause early wakings.
- Rule out sleep disorders: If your sleep falls within the recommended amount but you’re experiencing excessive daytime sleepiness or other sleep deprivation symptoms, it may indicate you’re getting low quality sleep. Be sure to speak with a doctor if you’re concerned about your sleep quality to learn if a sleep disorder may be the cause.
The environment you sleep in may be having an effect on how you sleep as well.
- Bedroom environment: Try to optimize your bedroom environment for sleep. To ensure quality sleep, make sure your bedroom is dark, cool, and quiet. Remove electronic devices like TVs and computers to help eliminate distractions.
- Watch light levels: Getting too much light exposure at night or not enough light throughout the day can contribute to sleep problems. Keep light exposure low for one to two hours before bedtime. Avoid exposing yourself to artificial lights before bedtime.
- Don’t use electronics devices: Electronic devices like smartphones, computers, and TVs emit blue light, which can make it harder to fall and stay asleep. To reduce the likelihood of sleep disruptions, avoid using devices with backlit electronic screens in bed.
Frequently Asked Questions about Sleep Calculators
If you wake up feeling tired, you may be experiencing a phenomenon called sleep inertia, which is a state of drowsiness and confusion that may last for up to an hour. This state of “sleep drunkenness” can happen if you are awoken during stage 3 NREM sleep. For some people, repeated episodes of sleep inertia may be a sign of an underlying sleep or mood disorder.
No — when you acquire a sleep debt due to sleep deprivation, it’s not possible to catch up by sleeping more at another time. Sleeping more may help with daytime sleepiness, but long-term sleep deprivation can impact your health. It’s important to ensure you’re regularly getting enough sleep each night.
Older adults should get about seven to eight hours of sleep a night, which is slightly less than other adults. When people get older, their sleep patterns change which often leads to earlier wake times and bedtimes.
You can use a sleep diary or an electronic device to help you track your sleep at night. If you’re tracking your sleep manually, write down the time you fall asleep and the time you wake up, as well as any nighttime awakenings.
Try to get enough sleep each night to avoid daytime tiredness and exhaustion. Work to improve your sleep hygiene and practice healthy sleeping habits. In addition, be sure to get some sunlight and physical activity during the day by going outside. Speak to a doctor if you constantly need to take a nap or have excessive daytime sleepiness.
If you are regularly getting less than the recommended amount of sleep for your age, sleeping longer may help you feel better. However, the duration of your sleep is only one aspect of your sleep health. The quality of your sleep also matters. Consider whether your current sleep hygiene and bedtime routine could be changed to help you get better sleep.