How to use these results

Pick the one closest to tonight

You don't have to chase the longest option. The closest realistic bedtime is usually the most useful one.

Give yourself a buffer

These times assume you take ~15 minutes to fall asleep. Start winding down earlier.

Consistency beats perfection

Going to bed within the same 30-minute window each night tends to help more than one long sleep.

Why 90-minute cycles (and when not to insist on them)

Adult sleep moves in cycles of roughly 80–110 minutes, with most people averaging about 90 minutes. A full night usually contains four to six of these cycles. Waking near the end of a cycle — when sleep is lightest — tends to feel easier than waking in the middle of deep sleep.

We use 90 minutes as a working average and add your fall-asleep buffer on top, so each suggestion lines up with the end of a cycle. Treat the times as windows of ±15 minutes rather than exact targets. If you cannot reach a 90-minute boundary, prioritize total sleep length (a common adult range is 7 to 9 hours per the CDC and the American Academy of Sleep Medicine) over hitting a precise cycle.

Recommended sleep by age (reference)

Recommended sleep length shifts with age. The figures below summarize the ranges from the American Academy of Sleep Medicine (AASM) and the CDC. Treat them as a starting point — individual needs vary.

Teens (14–17)	8–10 hours
Young adults (18–25)	7–9 hours
Adults (26–64)	7–9 hours
Older adults (65+)	7–8 hours

These reference ranges assume healthy adults. Pregnancy, recovery from illness, and shift work may shift the target.

If I go to bed now, when should I wake up?

The same 90-minute cycle math works if you start from the current time. Add your fall-asleep buffer (15 minutes is a common default), then look 4 to 6 cycles ahead and pick the option closest to the wake time you can actually hit.

Lying down at 23:00
Falling asleep around 23:15. Four cycles points to 05:15, five cycles to 06:45, six cycles to 08:15. Pick the closest to your real alarm.
Lying down at 00:30
Falling asleep around 00:45. Four cycles points to 06:45, five cycles to 08:15. If five cycles is too late, choose four cycles and protect the next nights to repay sleep debt.

For wake-time math the other way (you know the wake time, want a bedtime), use the input above — that is the main mode of this tool.

Turn this into an actual plan

Evening Routine Builder lays out a minute-by-minute wind-down to your bedtime.

Want to start from a wake time instead?

Bedtime Calculator works backwards from your wake time, with minimum / recommended / extended options.

FAQ

Why 90-minute cycles?

Adult sleep typically runs in cycles of about 90 minutes. Waking between cycles — rather than in the middle of deep sleep — can feel easier. Cycle length varies by person, so treat these as estimates.

Is this medical advice?

No. These tools offer general guidance for people who are generally healthy. If you have ongoing sleep issues, please see a qualified clinician.

What if my fall-asleep time is longer?

Adjust the field — the calculator will recompute. If you regularly need more than 30 minutes to fall asleep, that itself is worth looking into.