Wake times
If your alarm is set for 8:00am, when should you go to bed?
Remote work moved a lot of alarms to eight, and for late chronotypes that was the single best thing to happen to their sleep in a decade. For everyone else it mostly moved bedtime an hour later and changed nothing.
In short
To wake up at 8:00am feeling like you finished a cycle rather than got cut off inside one, go to bed at 12:15am. That is 7h 30m of sleep across 5 full cycles, plus the fifteen minutes it takes most people to drop off. If you can get to bed at 10:45pm you get 9h, and 1:45am still leaves you 6h.
- Lights out for a full night
- 12:15amLights out for a full night5 cycles, 7h 30m asleep
- Length of an average sleep cycle
- 90 minLength of an average sleep cycleReal ones run 70 to 120
- Added for falling asleep
- 0h 15mAdded for falling asleepMost calculators forget this
| Cycles | Lights out | Time asleep | What it is good for |
|---|---|---|---|
| 6 | 10:45pm | 9h | A long night. Worth aiming at if you are paying back sleep debt or training hard. |
| 5 | 12:15amAim here | 7h 30m | The target most adults should hold on a normal week. |
| 4 | 1:45am | 6h | Short, but a whole number of cycles, so you surface from a lighter patch. |
| 3 | 3:15am | 4h 30m | An emergency night. Fine occasionally, damaging as a pattern. |
An 8am alarm suits your body clock or it does not
Six cycles before an 8am alarm means lights out at 10:45pm, which is a comfortable bedtime by any standard, and that combination gives you a genuinely long night. Five cycles means 12:15am, which is where most people who set an 8am alarm actually are.
The interesting question at this hour is not how much sleep you are getting but whether you are getting it at the right time for you. A late chronotype waking at eight is finally sleeping in phase. An early chronotype waking at eight is often lying awake from half six and calling it a lie-in.
- Five cycles: bed at 12:15am
- Six cycles: bed at 10:45pm
- The rMEQ questionnaire in Tock onboarding will tell you which of those two people you are
A late alarm makes light exposure your job
When you wake at eight in winter, the first two hours of your day can pass without you seeing anything brighter than a laptop. That is enough to leave your body clock drifting later week by week, which is how a comfortable 8am gradually becomes an uncomfortable 8:45.
Get outside within an hour of waking, even for ten minutes, even under cloud. Outdoor light on an overcast day is still an order of magnitude brighter than a lit room, and it is the cheapest intervention on this entire page.
The table is an average, and your night is not
Ninety minutes is the number everyone quotes because it is the mean. In a real night your first cycle tends to run short, the middle ones stretch, and by the last hour before 8:00amyou are cycling faster and spending more of it in light sleep and REM. So the table gets you to roughly the right bedtime, and then the last half hour is a coin toss.
That last half hour is the entire argument for a smart alarm. Tock watches the thirty minutes before 8:00am on two channels, movement from the accelerometer and sound from the microphone, and rings a little early if it finds a lighter moment. If it does not find one,8:00am rings exactly as you set it. You can read more inhow smart wake works, or start withsleep cycles explained if the arithmetic above is the part you want to understand properly.
Questions people ask
What time should I go to bed to wake up at 8am?
12:15am for five cycles, 10:45pm for six. If you want a full night without a very late bedtime, eleven o clock lands you comfortably between the two.
Is waking up at 8am late?
Only relative to a schedule. Plenty of people with a genuine late chronotype do their best work on an 8am start and feel worse on a 6am one no matter how long they have been doing it. Consistency is the thing that matters, not the number.
Why do I feel groggy after eight or nine hours of sleep?
Long sleep is not automatically good sleep. Grogginess after a long night usually means the alarm caught you in deep sleep, or the night was broken up more than you remember. A morning report that shows the shape of the night is more useful here than the total.
Other wake times
The same maths, run for a different alarm.
- Waking up at 4:00amBedtimes by sleep cycle for a 4:00am alarm.
- Waking up at 4:30amBedtimes by sleep cycle for a 4:30am alarm.
- Waking up at 5:00amBedtimes by sleep cycle for a 5:00am alarm.
- Waking up at 5:30amBedtimes by sleep cycle for a 5:30am alarm.
- Waking up at 6:00amBedtimes by sleep cycle for a 6:00am alarm.
- Waking up at 6:30amBedtimes by sleep cycle for a 6:30am alarm.
- Waking up at 7:00amBedtimes by sleep cycle for a 7:00am alarm.
- Waking up at 7:30amBedtimes by sleep cycle for a 7:30am alarm.
- Waking up at 8:30amBedtimes by sleep cycle for a 8:30am alarm.
- Waking up at 9:00amBedtimes by sleep cycle for a 9:00am alarm.
Elsewhere on the site
A different corner of the same problem.
- Wake tonesCustom alarm soundTock comes with 18 wake tones, and if none of them suit you it takes your own audio as the alarm instead. Whatever you choose still gets scheduled through Apple's AlarmKit, so the silent switch, an active Focus and a fully closed app have no bearing on whether it rings.
- Head to headHeadspace Sleep vs PzizzIf you nap in the afternoon, or you get bored hearing the same track night after night, Pzizz. If you want to be taught how to wind down and to still be doing it in three months, Headspace Sleep.
- FeaturesAlarm on silentTock's alarms are registered with iOS through Apple's AlarmKit framework rather than played by the app in the background. That is why they ring with the ringer off, through a Focus, with Tock closed, on the native full-screen alert.
- Sleep soundsWhite noiseWhite noise holds equal power in every one hertz band, which makes it the brightest of the sleep noises and the best at covering thin, sharp sounds: keys in a lock, a running tap, a voice through a wall. That same brightness is why plenty of people last about an hour before switching to pink or brown.
- Tock for youTravellers with jet lagYou landed, you are on local time on paper, and your body is running four or eight hours behind. Wide awake at 3am, unusable at 3pm, and it lasts roughly a day per time zone.
- AlternativesTock vs RiseChoose Rise if planning your day around energy peaks and a running sleep debt is what actually changes your behaviour. Choose Tock if you want the alarm itself to be smarter, the night recorded from the phone, and a coach that can talk about what it heard.
An alarm at 8:00am does not have to feel like 8:00am
Tock watches the half hour before your alarm and rings a little early if it finds a lighter moment. Your set time is always the fallback, so you are never late.