How-to Guide 6 min read

What Time Should I Go to Bed to Wake Up at 6 AM? Bedtime Chart

Bedtimes for 5, 5:30, 6, 6:30, 7 and 8 AM alarms based on 90-minute sleep cycles, how the sleep calculator works out each time, and which row to pick.

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The short answer

To wake up at 6:00 AM after five full sleep cycles, be in bed by about 10:15 PM. For six cycles, aim for 8:45 PM; for four cycles, 11:45 PM. These times assume each cycle lasts about 90 minutes and that you take around 15 minutes to fall asleep, which is exactly how the Sleep Calculator works. Type any wake-up time into it and it gives you the three bedtimes instantly.

Five cycles (7.5 hours of sleep) is the sensible default for most adults. Four cycles is only 6 hours, which is below the 7 hours or more that sleep medicine bodies recommend for adults.

Bedtime chart for common wake-up times

Every time in this table was produced with the same formula the calculator uses: wake-up time minus (15 minutes + number of cycles × 90 minutes).

Wake-up time6 cycles (9 h sleep)5 cycles (7.5 h sleep)4 cycles (6 h sleep)
5:00 AM7:45 PM9:15 PM10:45 PM
5:30 AM8:15 PM9:45 PM11:15 PM
6:00 AM8:45 PM10:15 PM11:45 PM
6:30 AM9:15 PM10:45 PM12:15 AM
7:00 AM9:45 PM11:15 PM12:45 AM
7:30 AM10:15 PM11:45 PM1:15 AM
8:00 AM10:45 PM12:15 AM1:45 AM
8:30 AM11:15 PM12:45 AM2:15 AM

Read the row for your exact alarm time rather than rounding. A 30-minute change in your alarm moves every bedtime by the same 30 minutes, so a 6:30 AM alarm with five cycles means bed at 10:45 PM, not 10:15 PM.

How the calculation works

The Sleep Calculator uses two fixed assumptions:

  • One sleep cycle = 90 minutes. A cycle moves through lighter sleep, deep sleep and REM (dream) sleep. The idea is that waking near the end of a cycle, rather than in the middle of deep sleep, feels less groggy.
  • Falling asleep takes about 15 minutes. This is added on top of the cycles.

So for a 6:00 AM alarm and five cycles:

  • Five cycles × 90 minutes = 450 minutes (7 hours 30 minutes).
  • Add 15 minutes to fall asleep: 465 minutes (7 hours 45 minutes).
  • Count back 7 hours 45 minutes from 6:00 AM: 10:15 PM.

    • For six cycles it is 15 + 540 = 555 minutes (9 hours 15 minutes) back from 6:00 AM, which is 8:45 PM. For four cycles it is 15 + 360 = 375 minutes (6 hours 15 minutes) back, which is 11:45 PM.

    You can do this in your head: each extra cycle moves your bedtime 1.5 hours earlier.

    How to use the Sleep Calculator

  • Open the Sleep Calculator.
  • Choose I want to wake up at….
  • Enter your alarm time in the time box.
  • Read the three results. The tool lists 6 cycles (labelled Ideal), 5 cycles (Good) and 4 cycles (Minimum), with the hours of sleep for each.

    • It also works the other way. Choose I want to go to bed at…, enter a bedtime, and it shows the wake-up times that land at the end of 6, 5 or 4 cycles. For example, going to bed at 11:00 PM gives wake-up times of 8:15 AM, 6:45 AM and 5:15 AM.

    The calculation runs in your browser and the results update as soon as you change the time.

    Which row should you pick?

    The cycle labels in the tool are a starting point, not medical advice. A few practical rules help:

    • Adults: start with five cycles. The American Academy of Sleep Medicine and the Sleep Research Society recommend that adults aged 18 to 60 sleep seven or more hours a night on a regular basis. Five cycles gives 7.5 hours of sleep, which fits. Four cycles (6 hours) falls short, so treat it as an occasional fallback, not a plan.
    • If you regularly need an alarm to drag you out of bed, try six cycles for a week and see whether you wake more easily.
    • If you fall asleep in five minutes or lie awake for 30, the 15-minute assumption is off for you. Shift your bedtime by the difference. Someone who usually takes 30 minutes to drop off should go to bed 15 minutes earlier than the chart says.

    Why 90 minutes is an average, not a rule

    Ninety minutes is a convenient average. Real cycles vary from person to person and also change through the night, with more deep sleep early on and more REM sleep later. That means no calculator can guarantee you will wake at the exact end of a cycle. What the cycle approach does well is give you a consistent target that keeps your total sleep in a healthy range and stops you from picking an arbitrary bedtime like "around midnight".

    If you wake up a few minutes before your alarm and feel alert, that is a good sign the timing suits you. If you still feel groggy, move your bedtime 15 minutes earlier or later for a few nights and compare.

    Worked examples

    School run at 6:30 AM. Five cycles means bed at 10:45 PM. If you know you need 30 minutes to wind down, start that routine at 10:15 PM.

    Early shift at 5:00 AM. Five cycles means bed at 9:15 PM, which is hard for many people. The realistic choice is often 10:45 PM (four cycles, 6 hours of sleep), but if early shifts are your normal week, that is a regular shortfall. It is worth trying to make 9:15 PM work, at least on most nights.

    Weekend lie-in to 8:00 AM. Five cycles means bed at 12:15 AM. Be careful with big weekend shifts: going to bed two hours later on Friday and Saturday makes Sunday night's 10:15 PM bedtime much harder.

    Common mistakes

    • Forgetting the time to fall asleep. "7.5 hours before 6:00 AM" is 10:30 PM, but if it takes you 15 minutes to drift off you get only 7.25 hours of sleep. The calculator already adds the 15 minutes.
    • Counting time in bed as sleep. Scrolling on your phone after lights out does not count. The bedtime in the chart is when you are ready to sleep.
    • Using the four-cycle time every night. It is labelled Minimum for a reason. Six hours a night is below the adult recommendation.
    • Changing the alarm but not the bedtime. If your alarm moves from 7:00 AM to 6:00 AM, your bedtime should move one hour earlier too.
    • Expecting perfect results on night one. Give a new bedtime a week before judging it.

    When a calculator is not enough

    If you sleep seven or more hours and still wake up exhausted, snore loudly, stop breathing during sleep (as noticed by a partner) or struggle to stay awake during the day, talk to a doctor. A bedtime chart cannot detect sleep disorders.

    Related tools and guides

    Frequently asked questions

    What time should I go to bed to wake up at 6 AM?

    For five 90-minute sleep cycles plus about 15 minutes to fall asleep, go to bed at 10:15 PM. For six cycles it is 8:45 PM, and for four cycles 11:45 PM.

    How many sleep cycles should I aim for?

    Five cycles (7.5 hours of sleep) suits most adults. Medical bodies recommend that adults sleep seven or more hours, so four cycles (6 hours) should only be an occasional fallback.

    Does the sleep calculator include time to fall asleep?

    Yes. It adds 15 minutes to the sleep cycles. If you usually take longer, go to bed earlier by the difference.

    Can I calculate wake-up times from a bedtime instead?

    Yes. Choose "I want to go to bed at" and enter your bedtime. For example, an 11:00 PM bedtime gives wake-up times of 8:15 AM, 6:45 AM and 5:15 AM.

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