Bedtime calculator: what time should I go to bed?
Tell us when the alarm goes off. We'll work backwards in full 90-minute sleep cycles, plus the time it takes you to drift off, to find the bedtimes that let you wake between cycles.
Calculator
Fine-tune: 15 min to fall asleep · 90-min cycles
Most adults take 10–20 minutes to fall asleep. Cycles vary between about 80 and 110 minutes across people and across the night; 90 is the average.
To wake at 7:00 am at the end of a cycle, try to be in bed at one of these times:
Shortcuts: W wake-up mode, B bedtime mode, N sleep now, 1–4 pick a result.
Bedtimes for common wake-up times
Each bedtime includes 15 minutes to fall asleep. The highlighted column — five cycles, 7 hours 30 minutes of sleep — is the one most adults should aim for.
| Wake-up time | 6 cycles (9 h) | 5 cycles (7.5 h) | 4 cycles (6 h) |
|---|---|---|---|
| 4:30 am | 7:15 pm | 8:45 pm | 10:15 pm |
| 5:00 am | 7:45 pm | 9:15 pm | 10:45 pm |
| 5:30 am | 8:15 pm | 9:45 pm | 11:15 pm |
| 6:00 am | 8:45 pm | 10:15 pm | 11:45 pm |
| 6:30 am | 9:15 pm | 10:45 pm | 12:15 am |
| 7:00 am | 9:45 pm | 11:15 pm | 12:45 am |
| 7:30 am | 10:15 pm | 11:45 pm | 1:15 am |
| 8:00 am | 10:45 pm | 12:15 am | 1:45 am |
| 8:30 am | 11:15 pm | 12:45 am | 2:15 am |
| 9:00 am | 11:45 pm | 1:15 am | 2:45 am |
How to use your bedtime
The number on the screen is when you should be in bed with the lights off and the phone down — not when you start getting ready. Build a 20–30 minute wind-down before it: dim the lights, set tomorrow's things out, read something on paper.
If you can't hit the recommended time tonight, it's usually better to go to bed at the next cycle boundary than to split the difference. Going to bed 45 minutes late can put the alarm right in the middle of a cycle.
Why the wake time comes first
Your body clock is anchored most strongly by when you get up and see daylight. Keeping the alarm steady seven days a week and moving the bedtime to fit is the pattern sleep clinicians generally recommend for a stable rhythm.
When the bedtime feels impossible
- You're not sleepy at the recommended time. You might be an evening type — take the chronotype quiz. Shift bedtime earlier by 15 minutes every few nights rather than all at once.
- You lie awake for ages. Raise the fall-asleep slider to match reality, check your afternoon coffee with the caffeine cutoff calculator, and measure how much of your time in bed is actually sleep with the sleep efficiency calculator.
- You're setting a bedtime for a child or teen. Children need more sleep; see sleep needs by age and pick 6 cycles for teenagers.
Questions people ask
What time should I go to bed to wake up at 6 am?
For five 90-minute cycles plus 15 minutes to fall asleep: 10:15 pm. For six cycles: 8:45 pm. For four cycles: 11:45 pm.
What time should I go to bed to wake up at 7:30 am?
Aim for 11:45 pm (five cycles) or 10:15 pm (six cycles), assuming about 15 minutes to fall asleep.
What time should a teenager go to bed?
The AASM recommends 8–10 hours for 13–17 year olds, so six cycles (9 hours) is a good target. For a 7 am wake-up that means lights out around 9:45 pm.
Why does the calculator add 15 minutes?
That is a typical time for a healthy adult to fall asleep (sleep latency). If you usually take longer or shorter, change it under "Fine-tune" and all bedtimes update.
Is going to bed at the same time every night important?
Regularity helps. Research on sleep regularity (for example, work from the Harvard/Brigham sleep groups) links consistent timing to better alertness, but the wake time is the stronger anchor.