What Time Should I Go to Bed? Sleep Cycles Explained (With Examples)

Your correct bedtime is not simply the time at which you subtract eight hours from the alarm time. Your sleep consists of cycles that last about 90 minutes, and the position in these cycles in which your alarm wakes you makes a huge difference in how alert you will feel upon rising. If you wonder at which time you should go to bed tonight, you can find the solution to your question for the most widespread wake-up times here, followed by an explanation of how these calculations work. 

If you need a specific time, not provided in the tables below, use our Wowbeds Sleep Calculator.

The short answer: bedtimes for common wake-up times 

Set an awakening time and then choose a sleeping time accordingly. This gives you 15 minutes to go to sleep and places the alarm at the completion of the entire cycle.

The 5 or 6 cycles will be best for the majority of adults. The 4 cycles column will only be for those nights when you want to stay up very late, not every night. This is just an initial guideline, since everyone’s cycles may be different on any particular night, and you can alter by 15 minutes on each side.

How sleep cycles work 

What happens in a 90-minute cycle 

Throughout the night, you cycle through the stages of sleep from four to six times. There are four stages in total: three non-REM stages and one REM stage. In simple terms, they work like this: 

• Light sleep (the first two stages): You fall asleep; your body relaxes, and you can be easily awakened.
• Deep sleep: Your breathing becomes slower; you are hardest to awaken. Deep sleep occurs in the first part of the night.
• REM sleep: Your brain activity increases; dreaming is most intense in this stage. Length of REM increases throughout the night.

One full cycle takes an average of 90 minutes but can range between 70 and 120 minutes. The first sleep cycle may also be a bit shorter. This is the reason why any bedtime schedule is not precisely accurate.

Why waking mid-cycle feels so bad 

If an alarm wakes someone from deep sleep, then one may experience a state of being heavy and slow. This condition is known as sleep inertia. It is easy to wake up when someone is at the end of the cycle when they have lighter sleep.

How to work out your own bedtime 

Use your wake-up time, subtract 90 minutes per sleep cycle needed, and subtract 15 minutes more for falling asleep. For example, if you need to get up at 6:00 am and need five cycles:

• Seven-and-a-half hours is needed for five sleep cycles. 6:00 am less 7.5 hours is 10:30 pm.
• Subtract 15 minutes for falling asleep: 10:15pm.
• Go to bed and turn out the light at 10:15pm.

If your time to fall asleep takes longer than 15 minutes, make your bedtime even earlier.

Also, remember the rhythm of your body. People are either early birds or night owls; thus, the bedtime which is absolutely ideal from all sides may take some time to get used to. If you do not feel sleepy at the calculated time, turn down the lights, relax for 30 minutes and let your body learn a new schedule during a week or two.

Worked examples

What time to go to bed to wake up at 5am

For a 5am awakening, try to be asleep by 9:15pm for five sleep cycles (7.5 hours) or 7:45pm for six. In the case that 9:15pm is not possible, 10:45pm will give you four sleep cycles. This is sufficient for one night but insufficient to be repeated consistently.

Early awakenings are where having a consistent wake time is important. If you wake up at 5am on weekdays and sleep until 9am on weekends, you will drift backwards, and Monday mornings will be extreme discomfort.

What time to go to bed to wake up at 6:30am 

In case you are trying to set your alarm at 6:30am, then you will need to sleep at either 10:45pm for five cycles or 9:15pm for six. In case your bedtime is at 12:15am, you will get four sleep cycles. If your 6:30am alarm is for the school run, a set routine makes mornings easier for the whole family. Getting to sleep earlier will be easy once you have maintained a consistent wake-up time each morning.

If I sleep now, what time should I wake up? 

Count 15 minutes for falling asleep, and then add 90 minutes for each interval afterwards.

Wanting to go to bed past midnight but have to wake up early? Four sleep cycles after a midnight bedtime will make your wake-up time 6:15am. This math is applicable to whatever bedtime you have, even for those with a rotating shift system. Always make sure your environment is as dark as possible.

How many hours of sleep if I go to bed at 10pm and wake at 7am? 

Nine hours spent in bed from 10 p.m. until 7 a.m. With allowance for 15 minutes to fall asleep and a few moments of waking up, this makes for approximately 8.5 hours of sleep, which falls within the ideal range of 7 to 9 hours for adults.

From the point of view of cycles, starting to sleep at 10:15pm puts you at the end of your fifth cycle around 5:45am and the end of your sixth cycle at 7:15am. Thus, an alarm set for 7am is close to the end of cycle number six, when sleep is lighter and REM sleep is at its longest. 

How many hours of sleep do adults need? 

Most adults require 7 to 9 hours every night. Older adults require 7 to 8 hours. This means that people require five to six sleep cycles. Teenagers require more sleep: 8 to 10 hours a night. So, use the calculator while fixing sleeping times for other members of your family. The best way is to check your feelings. If you sleep for 7 hours or more and still feel sleepy during the day, you may be getting enough hours but not good quality sleep. Read our article on how much sleep adults require for more information.

Why do I keep waking up multiple times a night?

Normal waking vs a problem worth checking

Brief wake-ups at night are considered normal. People generally come up for a moment between cycles, and many of them tend to forget about this occurrence. This issue should be investigated in case you frequently awaken during the night, lie awake for an extended period, and feel unrefreshed in the morning.

The common causes are as follows:

• Alcohol consumption before going to bed. It may help you to fall asleep, but it usually disturbs your sleep cycles later on.
• Consumption of caffeine in the afternoon or evening.
• Stress and an active mind in the early hours.
• The necessity of urination, usually associated with the consumption of liquids before going to bed.
• Hormonal shifts, including night sweats during perimenopause and menopause.

This is general information and does not replace professional advice. Consult your doctor in case you usually awaken almost every night for some weeks, someone has observed loud snoring and gaps in your breathing, and you feel sleepy during the day although you are having enough rest.

What in your bedroom can wake you up 

There are some factors that are right in front of you:

• Temperature: The body needs to cool down to be able to fall asleep. Warm environment, a thick doona or any bedding material that retains heat can cause discomfort, especially during humid summers here in Australia. Check out our guide to the best mattress for hot sleepers.
• Restless bed partner: If there is someone else in the same bed, their movements can disturb you even when you are in the light sleep stage. A Wowbeds Duo Mattress has pocket spring core construction that helps reduce partner movement and disturbances. 
• Body pains and pressure points: Moving around to find a comfortable position means that your mattress doesn't work well with your sleep posture. Here is our sleep posture guide.
• Lights and noises: Street lights, the early morning sun during summer days and an illuminated phone screen are included.

A mattress can help you with comfort, heat and bed partner disturbances, but this is just one of many factors. If you think that your mattress can be a reason, then remember that every Wowbeds mattress has a 120-night trial period and 10 year warranty.

Making your bedtime stick 

Knowing the right time is the easy thing. Getting yourself to bed at 10:15pm is hard.

• Fix your waking up time first, including weekends whenever possible. Your bedtime will follow suit.
• Create an alarm to give you 30-45 minutes to relax before bedtime.
• Exposure to light shortly after you wake up is essential in setting the clock for your sleep that night.
• Make sure your room is cool, dark and quiet, and charge your phone out of your bedroom.
• Wait for two weeks. One good night will not say too much, but a fortnight will.

For a more complete plan, see our article on the perfect night routine for sleeping.

Frequently asked questions

How long is a sleep cycle?
On average, a cycle takes 90 minutes, but individual cycles may vary between 70 minutes and 120 minutes. Four to six sleep cycles occur each night for most adults.

How many hours of sleep do adults need?
Most adults require between seven and nine hours per night, which is equivalent to five to six sleep cycles.

Is it better to wake at the end of a cycle?
Yes, usually. Waking up from light sleep feels more refreshing than waking up from deep sleep. Not all cycles are the same, so consider your bedtime schedule just as a guide and fine-tune it by 15 minutes.

Is 6 hours of sleep enough?
Not for most adults, on a regular basis. Four cycles should take care of any brief nights, but regular sleep below 7 hours has been associated with bad health and concentration.