Sleep Calculator

Sleep Calculator UK: How Much Sleep Do You Need? (2024)

Last updated: 31.10.2023 Reading time: 9 Min.

Sleeping just the right amount will help you feel fresh and alert.

Unfortunately, most people sleep either too little or too much and you may be asking yourself, how much sleep do I need? 😴

We'll dive into the science of sleep and how you can sleep better below.

But first, check out our free sleep calculator!

Sleep calculator UK

Calculate your optimal bedtime

We need the right amount of sleep to stay healthy and feel refreshed, but what does that mean for you?

Try our sleep calculator to find out. 👇

Sleep calculator
Put in your desired wake-up or going to bed time, hit "Calculate" and get instant advice!
Select your age
  • Average time it takes to fall asleep

If you'd like to wake up at , these would be your recommended going-to-bed times:

If you'd like to go to bed at , these would be your recommended wake-up times:

Why should you use a sleep calculator?

When we go to bed at night, we embark on a journey. 🧳

Our brain activity, breathing and body temperature change constantly during the night.

Although we don't move, we are very active. 🏃‍♂️

By the time we open our eyes again the next morning, our bodies have gone through several sleep cycles.

sleep cycle
We undergo 4 to 6 sleep cycles per night.

If we go through too few cycles or are awakened at the wrong point, it will have a negative impact on our rest, mood and performance throughout the day. 🌞

Getting enough sleep is just as important for your health as food and water.

In fact, getting the right amount of sleep can help prevent disease, boost immunity and improve mental health [1]! 👩

Our sleep estimator will help make sure you get your bedtime right.

Once you know the best time to sleep, you'll know when to set your alarm clock to get just the right amount of sleep!

What happens if you don't get enough sleep

There are only so many hours in the day, and with so many things competing for our attention, it's no surprise that many of us sacrifice sleep.

If you've ever gone for a night or two with not enough sleep, you'll know how awful it can feel. 😿

How much sleep do I need
Waking up when you haven't slept enough can leave you feeling grotty all day.

A 2021 YouGov survey [2] on the average sleep time in the UK found over 40% of British adults were getting less than the recommended 7 to 9 hours of sleep per night.

But what happens if we sleep too little?

Short-term sleep deprivation consequences:

  • Lack of energy
  • Irritability and mood swings
  • Slower reaction times

People who continuously don't get enough sleep can see its impact on their everyday lives.

Unfortunately, too little sleep can cause much more than temporary tiredness. 🤒

There are also some serious long-term health problems [3] tied to lack of sleep.

Long-term sleep deprivation consequences:

  • Getting sick more
  • Weight gain and diabetes
  • Cardiovascular diseases and problems
  • Increased risk of depression and anxiety
  • Reduced cognitive function
  • Hormonal imbalances

Knowing how much sleep you need and actually getting it can improve your life today and in the future. 👯

Day and night: the circadian rhythm

Circadian rhythms are 24-hour cycles [4] that are part of our body’s internal clock. ⏰

These rhythms help our bodies prepare for environmental changes, including when we eat and sleep.

Circadian rhythm

Because of our circadian rhythm cycle, our body begins producing melatonin [5] when the sun has set (generally at around 9 pm). 🌅

This is the body's sleep hormone.

Melatonin helps regulate our sleep-wake cycle, promoting a consistent and quality night of sleep. 💤

Sunrise and light stop melatonin production, and the body begins to produce the stress hormone cortisol to prepare us for the coming day.

If you want to ensure you get a great night's sleep, using our sleep cycle calculator to sleep according to UK seasons and your circadian rhythm can help.

Waking up happy
Waking up and going to bed at the right time can help us wake up feeling refreshed and happy.

For instance, you might find waking up earlier in summer easier because the sun rises earlier, triggering cortisol production.

An earlier bedtime or sunrise alarm clock could help [6] with this even further.

What is a sleep cycle?

A single sleep cycle for an adult human lasts an average of 90 to 110 minutes [7].

Each cycle is made up of four different sleep phases.

These phases repeat until the point when we wake up.

Sleep cycle

Each of the stages of sleep is characterised by certain features.

The deep sleep and REM sleep phases are especially important for our rest and recovery. 🔁

Phase 1 non-REM sleep: Falling asleep

The falling asleep phase begins from the moment we turn off the light and close our eyes. 🥱

This is where our heart rate, breathing and brain activity slow down.

This phase is unique as it is (usually) only part of our first sleep cycle.

In subsequent cycles, the body skips this phase and goes directly into a light sleep. 😴

Phase 2 non-REM sleep: Light sleep

While our eyes are still moving during the falling asleep phase, they come to rest completely during light sleep.

At the same time, our muscles slowly relax, and we slide into a deeper sleep. 💤

On average, we spend about half of the night in the light sleep phase.

Phase 3 non-REM sleep: Deep sleep

Finally, we reach the deep sleep phase, where our body can best recover. 💆

In this phase, our body activity is at its absolute minimum.

We are never more relaxed than during this phase. 🛌

The deep sleep phase is when our muscles, brain and immune system are able to recover.

We usually spend 30 minutes per sleep cycle in the deep sleep phase.

REM (Rapid Eye Movement) sleep

Suddenly, everything changes.

Our eyes begin to flicker, and our brain activity increases as we reach the REM phase. 🧠

This occurs between the end of one sleep cycle and the beginning of a new one.

The REM phase is where we dream.

Images, conversations, feelings and memories are awakened and classified in this phase. 🔎

The REM phase is essential for our memory, learning, creativity, and other cognitive functions [8].

After about 10 minutes in the REM phase, we either wake up briefly or return to light sleep.

Best time to wake up
A REM cycle calculator can help you find the optimal waking time.

The REM sleep calculator shows that the REM phase is the best time to get up. ⏰

The Oura Ring is a smart accessory that monitors your sleep stages and cycles and can enhance the quality of your sleep.

What is the best time to get up in the morning?

You’ll feel most rested when you get up at the end of a sleep cycle.

If, on the other hand, you are pulled out of sleep during the deep sleep phase, you will feel very tired.

With our sleep calculator, you’ll get up feeling ready to face the day! 😃

The sleep calculator shows you when you need to go to bed based on your wake-up time.

Best time to wake up

It makes sure you will have the time to go through enough complete sleep cycles to feel rested when you get up.

This allows your body and mind to recover overnight. 💪

How much sleep do you need for your age?

How much sleep a person needs depends on their age and how long it takes them to fall asleep.

But how much sleep do adults need compared to kids?

Babies need a longer sleep duration, while elderly adults need less sleep.

sleep requirements at different ages
A sleep calculator by age can help you find the optimal bedtime.

Our sleep cycle calculator takes different age groups into consideration – so everyone can use our sleep calculator! 🧮

Sleep calculator for kids

For young children, sleep is an important time to process the experiences of the day.

The younger the child, the stronger the stimuli they receive from their environment.

You can use our sleep calculator for kids and babies so you can get them to bed on time for a happy and healthy tomorrow.

Babies need more sleep

Newborns need the most sleep of any age group, totalling almost twice as many hours of sleep compared to adults. 👶

Babies need more sleep than adults

After all, babies are experiencing everything for the first time, and their brains need time to process these experiences. 🧠

The brain uses sleep to do this, which is why the amount of sleep needed is significantly higher for babies than for adults.

You can ensure your baby gets superior quality sleep with the best cot mattresses.

Our favourite cot mattresses:

Sleep calculator for women

Men and women need a similar amount of sleep.

But, studies suggest that, in general, women need approximately 11 minutes [9] more a night.

A recent YouGov study [10] actually found that almost half of the women surveyed woke up tired.

Women are more likely to:

  • Struggle to fall sleep
  • Wake during the night

Additionally, the physical differences in women and men can cause differences in sleep behaviour.

For instance, women are more likely to suffer from sleep disorders like insomnia, anxiety, and depression.

Why do women need more sleep?

Women's sleep quality is related to hormones.

Happy woman sleeping

Many women experience different depths of sleep during their menstrual cycle. 🌖

This is usually just before and after the start of menstruation.

In addition, many women report sleep disturbances during menopause.

Overheating during sleep
During menopause, many women's sleep is disturbed, for instance, by hot flushes.

Women tend to experience more dramatic fluctuations than men in their reproductive hormones during their monthly cycle and menopause.

How can women improve their sleep?

Keeping a sleep diary for a few months can help you understand the impact of your cycle on the quality of your sleep.

Improving sleep hygiene with a sleep planner can also help.

For instance, creating a bedroom environment and routine that promotes consistent, uninterrupted sleep is important. 🧘

This can help ensure you still go through the recommended number of 90-minute sleep cycles during the night.

Some women find that small adjustments to their sleep habits, such as taking a warm bath before bed, decrease sleep disturbances.

Sleep calculator for men

For restful sleep, it is important not to wake up in the middle of a sleep cycle.

However, many men wake up before the deep sleep phase due to breathing problems or loud snoring. 👃

Loud snoring is also a symptom of sleep apnoea, which can significantly impact the quality of sleep and quality of life.

Men do, in fact, snore more than women.

According to a study by the American Academy of Sleep Medicine [11], habitual snoring has been found in about 24 per cent of adult women and 40 per cent of adult men.

Both men and women are more likely to snore as they age. 👴

In many cases, an anti-snore pillow can reduce snoring and improve the quality of sleep.

A shower before bed can help you sleep better
A shower before bed can help you sleep better.

Better sleep hygiene and sleep habits, including showering, sleeping on clean sheets, and keeping a dark room, can help you get a great night's sleep.

How can you fall asleep faster?

Our sleep-wake rhythm is anchored in our genes and has existed for thousands of years.

Unlike our ancestors, the world we live in today never sleeps.

Trains, aeroplanes, cars, screens, mobile phones, televisions, laptops - there are always lights burning and sounds disturbing the night. 📱

In particular, the blue light emitted from mobile phones is known to be disruptive to sleep patterns as it has a stimulating effect on the body and your brain waves.

Living according to the natural rhythm of the sun has become increasingly difficult. 🌇

Many people complain about problems falling asleep, and sleep disorders are increasingly common.

Our article on how to fall asleep fast has all of our top tips.

Creating the right bedroom environment and adopting a few sleep rituals can assist, but sometimes all you need is one of the best sleep accessories to help you drift off into a comfortable sleep. 😴

Here are our favourite sleep accessories:

Sleep through the night with the right mattress

Getting a good night's sleep is almost impossilbe without the right mattress.

Our guide on the best UK mattresses can help you find one that will ensure you're snug, comfortable, and supported all night long.

Here are some of our favourite mattresses:

Will a sleep calculator help you?

Understanding your sleep cycle is an important part of making sure you get the right amount of sleep.

Our sleep calculator can help you calculate the amount of sleep you need for your age.

As you start to understand how much sleep you need, you can begin to make small adjustments to your sleep schedule and environment to get a better sleep. 😴

Using a sleep calculator is the perfect place to start!

Frequently asked questions

  • How do you use the sleep calculator correctly?

    To use our free online sleep calculator correctly, simply enter your age and the time you wish to either fall asleep or get up, click enter, and you will get your results instantly. 

    Depending on what you enter, different times will be displayed. 

    It is important not to sleep too little or too much.

    A sleep cycle should not be interrupted.

    Waking up mid-sleep cycle can leave you feeling more tired, even if you got more sleep.

    Our sleep calculator UK suggests bedtimes or wake-up times based on how many hours of sleep you need and how you can reach this without interrupting a sleep cycle.

  • What is polyphasic sleep?

    Polyphasic sleep involves sleeping over more than two periods per day.

    These sleep cycles usually include naps throughout the day and less sleep at night.

    Babies naturally have polyphasic sleep patterns.

    Some people believe polyphasic sleep can provide more cognitive benefits, like improved memory.

    However, research [12] does not support the idea that polyphasic sleep provides more benefits than monophasic sleep (one long period of sleep at night).

    Some people, such as police officers or others working unusual schedules, may have no choice but to have a polyphasic sleep schedule.

    Polyphasic sleep calculators suggest different quantities and patterns of sleep. 

    For instance, the Everyman [13] polyphasic sleep calculator advises sleeping 4 times a day, with a 3-hour nap during the night and three supplemental 20-minute naps during the day.

    This equals only 4 hours, which is not a long enough sleep duration according to most calculators or studies.

    You would only sleep for one or two 90-minute sleep cycles a day with the Everyman polyphasic sleep calculator.

    Studies [14] suggest that adults need between 7 and 9 hours of sleep daily.

  • What time should you go to bed if you have to get up at 6 in the morning?

    If you want to get up at 6 am, you should go to bed at either 8:30 pm or 10 pm, according to our sleep time calculator. 

    This way, you will get the optimal amount of completed sleep cycles.

    At 11:30 pm, you can still get some full sleep cycles if you work with this sleep timer.

    However, you should not go to bed any later if you want to get up at 6 am.

    Calculate sleep to adjust your bedtime and improve your overall health with our user-friendly online sleep calculator

  • Is waking up at 4 am healthy?

    Waking up at 4 am can be healthy as long as you are going to bed early enough to go through the optimal number of sleep cycles. 

    Ideally, you should aim to go through 5 to 6 full sleep cycles.

    To wake up at 4 am, you should go to bed at 7 pm or 8:30 pm, according to our bedtime calculator. 

    But keep in mind that it may be more difficult to fall asleep when it is still light outside so you'll need to adjust your sleep planner and habits accordingly. ☀

  • When is the best time to go to bed?

    There is no such thing as a "best" time to go to bed. 

    The important thing is to go through 5 to 6 full sleep cycles a day.

    In the best-case scenario, you would sleep at night for 7 to 9 hours.

    Our bodies are biologically tuned to produce melatonin in the evening when it is dark and cortisol during the day.

    Sleep Hero can help you decide the best time to sleep and wake up.

    Our bed time sleep calculator can recommend a bedtime based on your desired wake-up time and sleep cycles.

  • Is 6 hours of sleep enough?

    Most adults should be aiming for 5 - 6 complete sleep cycles per night. 

    With an average of 90 minutes per cycle, this puts the optimal amount of sleep time at around 7.5 hours, according to our sleep hours calculator. 

    So what if you can only get 6 hours of sleep

    Sometimes things happen, and sleep has to be interrupted, but, in the long term, 5-6 hours of sleep is not enough

    And ultimately, you won't feel refreshed if you wake mid-sleep cycle.

    The sleep calculator cycle tells us that if you sleep for 5 hours, you won't be completing a sleep cycle.

    In the long term, sleep deprivation can have significant effects on your overall health.

    With our how much sleep do I need calculator, you can easily find out the ideal amount of rest for your age and lifestyle.

  • Why do you need to get enough sleep?

    Sleep is important for your health, especially the deep sleep phase, when we give our body the opportunity to reset. 

    This is when our muscles, brain and immune system are able to recover.

    Sleep is when we can subconsciously process the experiences from our day and, finally, relax. 💆

    Our hours of sleep calculator will help you figure out the right amount of sleep you need. 

  • Do naps count towards your total amount of sleep?

    According to the National Sleep Foundation [15], not all naps are created equal. 

    Anytime you sleep, you will start to move through the different sleep stages

    Naps lasting 10 - 20 minutes are considered the best nap duration.

    These give your body time to recover without leaving you drowsy and suffering from sleep inertia when you awake. 

    Adults can typically tell when they are feeling drowsy, so if you feel like your body needs a rest, then it is a good idea to have a quick snooze!

    However, evidence [16] suggests regular napping is not good for you.

    So it's not ideal to always use naps to get your recommended 7 to 9 hours of sleep. 

  • Why are you still tired after 8 hours of sleep?

    If you're getting 8 hours of sleep but still wake up feeling tired, there's likely an issue with your sleep quality or sleep schedule.

    8 hours of disturbed sleep is not the same as 8 hours of undisturbed sleep.

    Shutting off lights and electronics at least 30 minutes before you sleep and ensuring your room is dark and quiet can help improve your sleep.

    Unfortunately, there's no perfect sleep quality calculator.

    However, tools like smartwatches and the Oura ring can help you monitor how long you're actually sleeping, if you're overheating or being disturbed, and what sleep phases you're going through.

    You may also want to try adjusting your sleep schedule with our calculator.

    For instance, if you are consistently waking in the wrong part of the cycle (Stage 3: deep sleep), you're likely to find waking up much tougher.

  • What is a sleep cycle calculator?

    A sleep cycle calculator is the same as a sleep calculator.

    Sleep calculators like the Sleep Hero sleep cycle calculator don't just help you work out how many hours of sleep you need.

    They also help you to work out what time you should go to bed according to the time you want to wake up and vice versa.

    The best bedtime or wake-up time isn't calculated purely on recommended sleep duration, it also takes sleep cycles into consideration.

    Our calculator will provide times at 90-minute intervals.

    This is because a sleep cycle is 90 minutes long.

  • References


Holly Matthews

Senior Content Writer

Holly has been a content writer at Sleep Hero UK since 2021. With an MA degree in literature and previous experience working at a leading UK bed retailer, she is committed to using her skills to guide others towards making better sleep choices.

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