Sleep Calculator

UK Sleep Calculator: Get Enough Sleep To Wake Up Feeling Your Best (2022)

Written by Kim

Last updated: 19.07.2022

6 Min.

Most people sleep either too little or too much.

Sleeping just the right number of hours to get up feeling fresh and alert the next morning is both an art form and a science.

If you want to sleep better, you should take the time to understand your sleep-wake rhythm and sleep cycles and get into a good sleep routine. 😴

You can get started with optimising your sleep by using our free sleep calculator!

Sleep calculator UK

Calculate your optimal bedtime

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.

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.

Getting the right amount of sleep can help prevent disease, boost immunity and improve mental health! 👩

Our sleep calculator will help make sure you get your bedtime right and know when to set your alarm clock to get just the right amount of sleep!👇

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

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:

Day and night: the circadian rhythm

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

These rhythms run in the background, carrying out essential biological functions.

One of the most important and most famous circadian rhythms is the sleep-wake cycle.

Circadian rhythm

Because of this cycle, at around 9 pm, when the sun has set, melatonin production in the body begins for most people. 🌅

Melatonin is the body's sleep hormone.

It is produced in the pineal gland from serotonin and makes us sleepy.

Just before sunrise, melatonin production stops and the body begins to produce the stress hormone cortisol to prepare us for the coming day.

What is a sleep cycle?

A single sleep cycle for an adult human lasts an average of 90 minutes.

Each cycle is made up of four different sleep phases.

These phases repeat until the point when we wake up.

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. 🔁

Sleep cycle

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 slows 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 step-by-step into a deeper sleep. 💤

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

Best time to wake up

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 sleep (Rapid Eye Movement)

Suddenly, everything changes.

From one second to the next, our eyes begin to flicker and our brain activity increases. 🧠

This is because we have reached the famous 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. 🔎

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

The end of a REM sleep phase is widely considered the best time to get up. ⏰

The Oura Ring is a smart accessory that monitors your sleep stages and cycles. For more advice, take a look at our Oura Ring review.

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 before you get up so you feel rested.

This allows your body and mind to recover overnight. 💪

We've also tested a few sleep gadgets to help with getting up at the right time.

These are our favourite sleep devices:

How much sleep do I need for my age?

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

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

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

Age Recommended hours of sleep Still OK
0 - 3 months 14 - 17 hours 11 - 19 hours
4 - 11 months 12 - 15 hours 10 - 18 hours
1 - 2 years 11 - 14 hours 9 - 16 hours
3 - 5 years 10 - 13 hours 8 - 14 hours
6 - 13 years 9 - 11 hours 7 - 12 hours
14 - 17 years 8 - 10 hours 7 - 11 hours
18 - 25 years 7 - 9 hours 6 - 11 hours
26 - 64 years 7 - 9 hours 6 - 10 hours
Over 65 years 7 - 8 hours 5 - 9 hours

Sleep calculator for babies and children

Babies need twice as many hours of sleep compared to adults. 👶

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.

Newborns need the most sleep of any age group.

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.

We’ve compiled some of the best cot mattresses to make sure your baby is getting the best possible quality of sleep.

One of our favourite cot mattresses is the Little Green Sheep Natural Twist cot bed mattress.

This is a dual-sided cot mattress made from 100% natural, organic materials, including coconut coir, latex, wool, and cotton.

Sleep calculator for women

The amount of sleep needed does not vary by gender. 🚺

Men and women need the same amount of sleep.

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

Women's sleep quality is related to hormones.

Happy woman sleeping

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

The majority of women who have trouble with sleep related to their menstrual cycle have problems just before and after the start of menstruation.

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

In addition, many women report sleep disturbances during the menopause.

Improving sleep hygiene, which means 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 sleep habits, such as taking a warm bath before bed, decreases 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 apnea, 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, 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

How can I fall asleep faster?

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

Unlike our ancestors, we face modern sleep problems.

The world we live in today never sleeps.

Trains, aeroplanes, cars, screens, mobile phones, televisions, laptops - there are always lights burning somewhere 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.

Modern problems need modern solutions.

We’ve rounded up some of the best modern sleep accessories from duvets to pillows that can help you drift off into a comfortable sleep. 😴

Here are our favourite sleep accessories:

Sleep through the night with the right mattress

The most important thing for a deep and healthy sleep is the right mattress.

You can find out which mattress would be best for you by checking out our best mattress reviews.

Here are our 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 I 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 in the middle.

  • What is our polyphasic sleep calculator based on?

    Our sleep calculator bases its calculation on the widely-accepted view that every person should go through five to six full sleep cycles in a night.

    One sleep cycle is 90 minutes long. 

    If you identify your desired time to get up or fall asleep, then add the number of sleep cycles, you get the result.

  • What time should I go to bed if I 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. 

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

    At 11:30 pm, you can still get some full sleep cycles. 

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

  • Is waking up at 4am 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, so, to wake up at 4 am, you should go to bed a 7 pm or 8:30 pm. 

    Keep in mind that it may be more difficult to fall asleep when it is still light outside. ☀

  • 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. 

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

  • Is 5 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. 

    So what if you can only get 5 hours of sleep

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

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

  • 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.

    To help you get a good night’s sleep, some simple rituals can help. 

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

  • Do naps count towards my total amount of sleep?

    Technically, yes, but according to the National Sleep Foundation, 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!


Let's be honest, writing and sleeping have always been my favourite activities. My favourite hoodie that I wore all through uni said 'All I want to do is drink coffee, create stuff and sleep' on it. Dreams really do come true! 

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