If you have ever lain awake at night wondering what time should I go to bed, you are not alone. It is a common question, and the answer matters more than most people think. The right bedtime is not just about enough hours. It is about waking at the right point in your sleep cycle, so you feel rested instead of groggy.
The honest answer to what time should I go to bed is that it depends on when you need to wake up. Your body sleeps in roughly 90-minute cycles, moving from light sleep into deep sleep and then REM sleep. Waking at the end of a cycle feels far better than being dragged out of deep sleep mid-cycle, even with the same total hours. That is why a well-timed 7.5 hours can feel better than a badly timed 8 hours.
What Time Should I Go to Bed? The 90-Minute Cycle Rule
To work out what time should I go to bed, start with your alarm and count backwards in 90-minute blocks, then add about 15 minutes for falling asleep. Most adults need five or six full cycles a night: 7.5 or 9 hours in bed. A free sleep calculator can do this maths for you in seconds, but the rule is simple enough to use on your own. Reading more about how sleep cycles work explains why waking at the end of a cycle feels so much better.
Use the table below to find what time should I go to bed for your usual alarm. Each row gives two options: six cycles (9 hours) and five cycles (7.5 hours), including 15 minutes to fall asleep.
| Wake-up time | Bedtime for 6 cycles (9 hours) | Bedtime for 5 cycles (7.5 hours) |
|---|---|---|
| 5:00 AM | 7:45 PM | 9:15 PM |
| 5:30 AM | 8:15 PM | 9:45 PM |
| 6:00 AM | 8:45 PM | 10:15 PM |
| 6:30 AM | 9:15 PM | 10:45 PM |
| 7:00 AM | 9:45 PM | 11:15 PM |
| 7:30 AM | 10:15 PM | 11:45 PM |
| 8:00 AM | 10:45 PM | 12:15 AM |
If your alarm falls outside this table, subtract 9 hours 15 minutes or 7 hours 45 minutes from your wake-up time. Pick the option that fits your evening and keep it consistent — your body clock loves routine more than a perfect number.
What Time Should I Go to Bed by Age?
Sleep needs change with age, so a teenager asking what time should I go to bed needs a different answer from a retiree. Children and teenagers need more sleep because their brains and bodies are still developing, while most adults do well on 7 to 9 hours. The official recommendations give a useful starting point for every age group:
- School-age children (6–12 years): 9–12 hours per night
- Teens (13–18 years): 8–10 hours per night
- Adults (18–64 years): 7–9 hours per night
- Older adults (65+ years): 7–8 hours per night
For example, a teenager who must wake at 6:30 AM and needs 9 hours should aim for around 9:00 PM in bed, allowing six cycles plus falling-asleep time. An adult with the same alarm who feels fine on 7.5 hours can aim for about 10:45 PM. Use these recommendations as a starting point, then adjust based on how you feel during the day. If you stay alert without an afternoon crash, your bedtime is probably right.
What Time Should I Go to Bed If You Are a Night Owl?
Chronotype, whether you are naturally a morning lark or a night owl, shifts your ideal bedtime. Night owls genuinely fall asleep later and wake later, and forcing a 9:30 PM bedtime when your brain is still wide awake usually means an hour staring at the ceiling. If your schedule allows, honour your chronotype. A night owl who starts work at 10 AM may do best with a 1:00 AM to 9:00 AM sleep window, while a lark may thrive on 10:00 PM to 6:00 AM.
Most jobs and schools, though, run on early schedules. If you cannot shift your wake time, shift your wind-down earlier instead. Dim the lights, cool the room and put screens away an hour before your target bedtime. Over a week or two, your body clock will move, and falling asleep at your planned time will get easier.
What Else Shifts Your Ideal Bedtime
Late caffeine is one reason the answer to what time should I go to bed moves later than planned. Caffeine can linger in your system for six to eight hours, so a 4 PM coffee can still be keeping you alert at 10 PM. Cut caffeine by early afternoon if you struggle to fall asleep. Screens matter too. Bright light from phones tells your brain it is still daytime, so switch to dim light and non-screen activities in the last hour before bed.
Consistency is the biggest lever of all. Going to bed and waking at the same times daily, weekends included, trains your body clock so you feel sleepy at the right time and wake naturally near your alarm. Exercise helps too, ideally finished a few hours before bed, and a cool, dark, quiet bedroom helps you fall asleep faster.
Frequently Asked Questions
What time should I go to bed if I wake up at 6 AM?
For a 6 AM alarm, the answer to what time should I go to bed is 10:15 PM for five sleep cycles or 8:45 PM for six cycles, including 15 minutes to fall asleep. Most adults should try 10:15 PM first.
Is 10 PM a good bedtime?
Yes, for many adults. A 10 PM bedtime with a 6 AM alarm gives roughly 7.5 hours of sleep, or five full cycles, which sits inside the recommended range for adults.
How many sleep cycles do I need each night?
Most adults need five or six cycles, about 7.5 to 9 hours. Children and teenagers need more, and older adults often need slightly less.
Does going to bed earlier always help?
Not on its own. An earlier bedtime only helps if you can actually fall asleep then. Match your bedtime to your wake time using the cycle rule, and keep it consistent.
What if I cannot fall asleep at my planned bedtime?
Get up, do something calm in dim light, and return to bed when you feel sleepy. Lying awake for long stretches teaches your brain to link bed with wakefulness.
Conclusion
So, what time should I go to bed? Start with your wake-up time, count back five or six 90-minute cycles, add 15 minutes to fall asleep, and adjust for your age and chronotype. Keep that time consistent, protect the last hour before bed from caffeine and screens, and let your body clock do the rest. A good bedtime is not one magic hour. It is a habit that fits your life, and once you find it, mornings get noticeably easier.