To wake up at 6:30 am, you should go to sleep at

If you go to sleep at 9:30 pm, you should wake up at

Recommended
6 Sleep Cycles
10:30 pm
9h 0m of sleep
Deep Sleep 1h 37m
Rem Sleep 2h 1m
5 Sleep Cycles
10:30 pm
7h 30m of sleep
Deep Sleep 1h 21m
Rem Sleep 1h 41m
4 Sleep Cycles
10:30 pm
6h 0m of sleep
Deep Sleep 1h 4m
Rem Sleep 1h 21m
3 Sleep Cycles
10:30 pm
4h 30m of sleep
Deep Sleep 0h 48m
Rem Sleep 1h 0m

About our sleep cycle calculator

Our 2026 UK Sleep Survey found only 32% of Brits always or often wake up feeling refreshed. It usually comes down to one of three things: too few hours in bed, an inconsistent routine, or waking in the middle of a deep sleep stage.

Our sleep calculator takes your target wake-up time (or bedtime) and works backwards to the nearest full 90-minute sleep cycle. That way, you’re more likely to wake during a lighter stage of sleep, feeling clearer-headed and less groggy.

What's the best time to go to bed?

For most adults, somewhere between 10 pm and 11 pm may align well with natural circadian rhythms. A study published in the European Heart Journal Digital Health tracked 88,000 UK Biobank participants aged 43-74 and found that those who fell asleep between 10 pm and 10:59 pm had the lowest risk of heart and circulatory disease over the following six years. Bedtimes at or after midnight were associated with the highest risk.

Researchers were careful to note that the study shows an association, not cause and effect. The link may relate to how well your sleep timing aligns with your circadian rhythm. Going to bed during your natural window of sleepiness could support better sleep quality and consistency, both of which are linked to long-term cardiovascular health.

The 10-11 pm window also aligns neatly with a 6-7 am wake-up, a common schedule that falls within recommended sleep ranges.

How much sleep do you need?

The amount of sleep your body needs shifts with age. The numbers below are the recommendations from the National Sleep Foundation:

Age Hours of sleep per night
0-3 months 14-17
4 months to 2 years 11-16
3-5 years 10-13
6-13 years 9-12
14-17 years 8-10
18-64 years 7-9
65 years and over 7-8

Our 2026 Sleep Survey found the average Brit spends 7.2 hours in bed but only 6.4 hours actually asleep. That’s a shortfall of around 40 minutes a night, or close to 5 hours over the course of a week.

If you wake up feeling flat most mornings, you might be oversleeping, undersleeping, or waking mid-cycle.

If you’re sleeping too much, you might:

  • Regularly sleep through your alarm
  • Struggle to get out of bed
  • Rarely feel refreshed
  • Feel sleepy no matter how many hours you clock

If you’re sleep-deprived, you might notice:

  • Trouble concentrating
  • Memory slips
  • Mood swings
  • Reduced alertness
  • Feeling anxious or stressed

Our 2026 Sleep Survey found that 54% of Brits experience low energy the day after a bad night, and 51% experience fatigue. For more, read our article on the signs of extreme tiredness.

What are sleep cycles?

A sleep cycle moves through four stages: three of non-rapid eye movement (NREM) sleep and one of rapid eye movement (REM) sleep. Each cycle lasts roughly 90 minutes. You’ll typically work through 5-6 of them in a full night.

The first half of the night is heavier on deep NREM sleep, where physical recovery happens. The second half tilts towards REM sleep, where the brain consolidates memory and processes emotion. Waking up at the end of a cycle (in light NREM) feels much easier than waking mid deep sleep, which is why our calculator times your bedtime around the 90-minute rhythm.

Calculating your ideal bedtime

Using our sleep cycle calculator gives you an ideal bedtime based on your wake-up time so that you can fit in the right number of cycles. It also helps you avoid waking during deep sleep. If you want to aim for 8 hours of sleep, you could also count backwards by the time you need to wake up to help you figure out when to go to bed.

Our 2026 Sleep Survey found that the average UK bedtime is 10:36 pm and the average wake time is 6:58 am, giving a window in bed of around 7.2 hours, with 6.4 hours of actual sleep. How does your schedule compare to that?

Sleep cycle FAQs

The basics are simple. Aim for 5 to 6 full cycles (7 to 9 hours in bed), and time your wake-up to land outside of deep sleep. Our calculator does that second bit for you. Sticking to a consistent schedule, even at weekends, trains your body to fall asleep faster and wake more naturally. Our guide to evening routines covers what that looks like.

Stress is one of the biggest things that throws a cycle off. Our 2026 Sleep Survey found racing thoughts (37%) and stress (28%) are the two most common reasons Brits lose sleep. Managing stress during the day tends to help more than any bedtime trick.

The sleep cycle calculator gives you a useful framework based on the average 90-minute cycle length. Individual cycles can vary between roughly 70 and 120 minutes depending on your age, stress levels, caffeine intake and general health. Treat the times as a guide, not a precise schedule. Try them for a week or two, and adjust as you feel.

Grogginess after a long night usually means you woke up in the middle of a deep sleep stage. It’s called sleep inertia, and it’s why timing your wake-up to the end of a cycle can matter more than the total hours you clock. Our 2026 Sleep Survey found only 32% of Brits always or often wake up feeling refreshed, so this is a very common experience.

Yes. As we age, we tend to spend more time in lighter stages of sleep and less in deep sleep, which is why older adults often report sleeping less soundly. Children and teenagers need more total sleep and generally get more deep sleep overall.

Force-sleeping rarely works. If the suggested bedtime feels too early, shift gradually, 15 minutes earlier every few nights, rather than jumping to a new schedule. Good sleep hygiene habits help your body adjust too.

For most adults, yes. Each cycle gives your body and brain a different kind of recovery, so skipping cycles means skipping some of that recovery. Younger adults and teens often need more, and individual needs vary. Use our calculator as a starting point and adjust based on how you feel over the next couple of weeks.

If you’re hitting your bedtime and wake time consistently but still feel wiped, the issue probably lives outside the schedule itself. Here is a quick checklist of what to look at next:

  • Your bedroom environment: Temperature, noise and light all affect how well your cycles run. Our 2026 Sleep Survey found 24% of Brits lose sleep because they’re too hot.
  • Your sleep hygiene: Caffeine timing, screen use and evening routines all influence how cleanly you move through the stages. Our full guide to sleep hygiene covers 15 practical tweaks.
  • Your mattress and bedding: The average British mattress is 6.4 years old, and 25% of us have never cleaned ours. Our mattress care guide and guide to how often to wash your bedding cover the essentials.

If tweaks aren’t helping, it’s worth speaking to your GP to rule out an underlying cause.