Sleep calculator
Going to bed at 11:00 PM? Here's when to wake up
Lights off at 11:00 PM, about 15 minutes to fall asleep, then whole 90-minute cycles. The best alarm times are 6:45 AM or 8:15 AM. Here's the full table, and what each common alarm time actually leaves you with.
Wake-up times that end on a full cycle
| Wake up at | Cycles | Time asleep | Verdict |
|---|---|---|---|
| 3:45 AM set alarm | 3 | 4h 30m | Emergency only |
| 5:15 AM set alarm | 4 | 6h | Short, but workable now and then |
| 6:45 AM set alarm | 5 | 7h 30m | Recommended |
| 8:15 AM set alarm | 6 | 9h | Recommended |
The two recommended rows are where most adults do best. Anything under five cycles is a deficit you will repay later in the week, and three cycles is the kind of night you should only have on purpose.
How much sleep each alarm time gives you from 11:00 PM
The other direction: if your alarm is already fixed by work or school, here is what a 11:00 PM bedtime actually leaves you with.
| Alarm set for | You sleep about | How that lands |
|---|---|---|
| 5:00 AM | 5h 45m | Under-slept; expect a hard morning |
| 5:30 AM | 6h 15m | Under-slept; expect a hard morning |
| 6:00 AM | 6h 45m | Slightly short — fine occasionally |
| 6:30 AM | 7h 15m | Slightly short — fine occasionally |
| 7:00 AM | 7h 45m | A full night for most adults |
| 7:30 AM | 8h 15m | A full night for most adults |
| 8:00 AM | 8h 45m | A full night for most adults |
| 9:00 AM | 9h 45m | A full night for most adults |
These are averages, not rules — real cycles run anywhere from 80 to 110 minutes and get shorter through the night. Use the times as good starting points, and if you consistently wake exhausted on enough hours, that's worth raising with a doctor rather than a calculator.
10:30 to 11:30 is where most people live — and where the margin runs out
This is the most common bedtime there is, and it pairs cleanly with the most common wake-up: six cycles from 11 PM puts you at 8:15, five at 6:45. For a 7 o'clock alarm that is a full night with nothing to spare, and that "nothing to spare" is the part to pay attention to.
With no buffer, small things decide the morning. Twenty minutes of phone in bed turns a 6:45 wake-up into four and a half cycles, which means the alarm now lands in deep sleep instead of at the end of a cycle. That is the difference between surfacing and being dragged out — same bedtime, same alarm, completely different morning. If your wake time is fixed by work or school, the honest move is to treat the bedtime in the table as the moment the lights go off, not the moment you get into bed.
The flip side is that this band responds fast to small changes. Even 15 minutes earlier, held for a week, moves you from the edge of five cycles to comfortably inside it — and most people feel that within a few days.
Picking the time is the easy half
A wake time that ends on a cycle makes the first minute easier. It does not make the decision for you. If you sleep through alarms or turn them off without remembering, the right time on the clock changes nothing, because the off button is still within reach.
WakeUpBroo fixes that half. It rings on your iPhone with no snooze and no dismiss button; to stop it you read a rotating code from wakeupbroo.com/code on a laptop or other device you left across the room. By the time you've walked over and typed it, the wake-up has actually happened.
Other bedtimes
Turning in a little sooner? See the wake times for going to bed at 10:30 PM. Running later tonight? See going to bed at 11:30 PM. For any other time, use the sleep calculator, or start from the alarm instead with the online alarm clock.
FAQ
Frequently asked questions
If I go to bed at 11:00 PM, what time should I wake up?
Going to bed at 11:00 PM and allowing about 15 minutes to fall asleep, six full sleep cycles end at 8:15 AM and five end at 6:45 AM. Either gives most adults a full night; pick the one that fits your morning and set the alarm for exactly that time.
Is 11:00 PM a good bedtime?
For most adults, yes. 11:00 PM leaves room for five or six full cycles before a normal morning alarm, which is the range most people feel best on. The bigger factor is keeping it consistent, including weekends.
What if I don't fall asleep within 15 minutes?
Then shift the table by however long you actually take. If it is routinely 45 minutes, add 30 to every wake time above — or, better, go to bed when you are sleepy rather than when the clock says, and hold the wake time fixed instead.
I set the right alarm and still sleep through it. Now what?
That is the half a calculator cannot solve. If you dismiss alarms half-asleep, you need one that cannot be stopped from bed. WakeUpBroo for iPhone has no snooze and no dismiss button — the alarm stops only when you type a rotating code from wakeupbroo.com/code on a device across the room.
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Picked a wake-up time? Make it stick.
Knowing when to wake up doesn't get you out of bed. WakeUpBroo has no snooze and no dismiss button — the alarm stops only when you read a rotating code from this website on another device. Free to download, 7-day free trial.
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