Wake times
If your alarm is set for 8:30am, when should you go to bed?
Students, freelancers and anyone whose first commitment is at ten tend to land here. The schedule is perfectly workable, and the thing that undoes it is almost always the weekend rather than the weekdays.
In short
To wake up at 8:30am feeling like you finished a cycle rather than got cut off inside one, go to bed at 12:45am. 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 11:15pm you get 9h, and 2:15am still leaves you 6h.
- Lights out for a full night
- 12:45amLights 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 | 11:15pm | 9h | A long night. Worth aiming at if you are paying back sleep debt or training hard. |
| 5 | 12:45amAim here | 7h 30m | The target most adults should hold on a normal week. |
| 4 | 2:15am | 6h | Short, but a whole number of cycles, so you surface from a lighter patch. |
| 3 | 3:45am | 4h 30m | An emergency night. Fine occasionally, damaging as a pattern. |
This hour drifts if you let it
An 8:30 alarm with a 12:45am bedtime is five full cycles and a reasonable night. The risk is that nothing external is holding the wake time in place. No school run, no train, no office. When the only thing enforcing the schedule is the alarm itself, the alarm tends to lose.
What usually happens is a slow slide. 8:30 becomes 9:00, the bedtime follows, and within a couple of months the day starts at eleven and the night starts at three. Nothing dramatic happened. Each individual night was only twenty minutes later than the last.
- Five cycles: bed at 12:45am
- Six cycles: bed at 11:15pm
- With no external anchor, the wake time is the only thing stopping the drift
Make the alarm harder to argue with
On a schedule with nothing external holding it up, the dismissal is the whole battle. An alarm you can silence with one thumb from under the duvet is not really an alarm, it is a suggestion.
Tock keeps ringing until you solve something, and the place missions are the strongest of the nine: photograph a spot you saved, or scan a barcode you left in the kitchen. Both mean standing up, and standing up is most of the job.
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 8:30amyou 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 8:30am 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,8:30am 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 8:30am?
12:45am for five cycles, 11:15pm for six. If the day has no hard start, the six cycle option is worth taking, because the flexibility that makes this schedule pleasant is also what makes it drift.
How do I stop my sleep schedule drifting later?
Hold the wake time, not the bedtime. Get up at the same time every day including weekends, get bright light in the first hour, and let sleep pressure move the bedtime for you. Trying to force an earlier bedtime while the wake time floats does not work.
Is it bad to wake up at 8:30 every day?
No. A consistent 8:30 is healthier than an inconsistent 7:00. The problems people attribute to waking late are usually problems of irregularity or of missing daylight, not of the hour itself.
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 8:00amBedtimes by sleep cycle for a 8:00am 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.
- FeaturesSleep soundsTock has 63 fall-asleep sounds. You can play four at a time, save the blend as a mix, and 42 of them carry a Far, Near or Close distance control. 22 are bundled recordings and the rest are generated on the phone as you listen, so they never loop.
- Sleep soundsFanA fan makes broadband noise from air turbulence plus a very quiet periodic thump from the blades, sitting somewhere between pink and brown in balance, which is why so many people sleep to one without ever calling it white noise. Tock uses a recording of an actual fan rather than generating it, because that blade rhythm is the thing that makes it read as a fan at all.
- Tock for youHeavy sleepersYou have slept through alarms you definitely heard, and turned some of them off without ever waking up. The problem is not your hearing. The part of you that swipes an alarm away is awake several minutes before the part of you that makes decisions.
- 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.
- RoundupsThe best snoring apps, ranked by what they're forSnoreLab is the best dedicated snoring app: recording and scoring your snoring is its only job, and its remedy tracking is more deliberate than anything else here. Tock is the better pick if you want snoring in context, inside a night that also carries your sleep, your alarm and playable audio of what the room actually sounded like.
- BedtimesGoing to bed at 1:30amWhere to put the alarm after a 1:30am lights-out.
An alarm at 8:30am does not have to feel like 8:30am
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.