Sleep calculator: when to go to bed and wake up

The short answer

Count back 7 to 9 hours of sleep plus about 15 minutes to fall asleep from the time you need to wake up. For a 7:00 a.m. alarm that means lights out between about 9:45 and 11:45 p.m. If your bedtime is much later now, move it 15 minutes earlier every few days instead of all at once.

How much sleep do you need?

Most adults need 7 or more hours of sleep a night: 7 to 9 hours from 18 to 64 and 7 to 8 hours from 65. Teens need 8 to 10 hours and children 6 to 12 need 9 to 12 hours. Babies, toddlers and preschoolers need 10 to 17 hours a day, naps included.

Source: the CDC, based on the American Academy of Sleep Medicine and National Sleep Foundation recommendations listed under Sources. These are ranges for healthy people. Some need a little more or less; how alert you feel during the day is a useful check.

How to make a sleep schedule you can keep

A sleep schedule is a fixed wake-up time, a lights-out time that leaves enough sleep for your age and a wind-down before it. Start from the time you need to be up on workdays, keep it on weekends too, then count back your hours of sleep plus the minutes you need to fall asleep.

1. Pick a wake-up time you can keep every day. The CDC’s first sleep habit is going to bed and getting up at the same time every day.
2. Count back to lights out. Take away your hours of sleep and about 15 minutes to fall asleep. The weekly sleep schedule above does it for every night.
3. Add a wind-down. Start 30 to 60 minutes before lights out: dim the lights, put the phone on its charger and do the same few calm steps each night. See how to build a bedtime routine.
4. Keep weekends close. A later weekend alarm moves Friday and Saturday nights later too, and Sunday night has to come back for Monday. The schedule shows that shift so you can see it.
5. Put it where you will see it. Print it for the bedroom door or save it as a phone wallpaper, and set a wind-down alarm.

Sleep schedule examples

Each example includes 15 minutes to fall asleep and a 30-minute wind-down. For other patterns, such as split or shift-work sleep, see types of sleep schedules. If your body wants a much later or earlier night than your alarm allows, take the chronotype quiz to see where you fall between a morning and an evening type.

Bedtime chart for common wake-up times

Lights-out times below include 15 minutes to fall asleep. Pick the column that matches how much sleep you usually need.

Why the calculator puts hours before sleep cycles

You will often read that you should wake at the end of a 90-minute sleep cycle. Cycles do average about 90 minutes, but they vary between people and change through the night, so an exact cycle count is a rough guide at best. The calculator shows cycles for reference and bases each option on total hours, which is what the sleep recommendations above are written in.

How to make a new bedtime stick

1. Fix the wake-up time first. A steady wake-up time, weekends included, anchors the rest of the schedule.
2. Get daylight soon after waking. Morning light helps move your body clock earlier; bright evening light pushes it later.
3. Start a wind-down alarm. Set an alarm 30 to 60 minutes before lights out to start your bedtime routine.
4. Shift in small steps. Use the shift planner above rather than moving an hour at once.

Short night behind you? The nap calculator times a 20-minute power nap or a full 90-minute cycle and warns you when a nap is too close to bedtime.

More help: what time should I go to bed, how to fix your sleep schedule and the personal 30-day evening routine plan. If you snore loudly, stop breathing during sleep or feel very sleepy in the day, talk to a doctor.

Frequently asked questions

How much sleep do I need?

Adults need 7 or more hours a night: 7 to 9 hours from 18 to 64 and 7 to 8 hours from 65. Teens need 8 to 10 hours, children 6 to 12 need 9 to 12 hours, and younger children need more, naps included. How you feel during the day is a useful check.

How much sleep do kids and teens need?

The American Academy of Sleep Medicine recommends 9 to 12 hours for children 6 to 12 and 8 to 10 hours for teens 13 to 18, on a regular basis. Choose the age band in the calculator to see bedtimes for that range.

What is a good sleep schedule?

One you can keep every day: the same wake-up time on weekdays and weekends, a lights-out time that leaves enough sleep for your age, and a 30 to 60 minute wind-down before it. For an adult waking at 7:00 a.m., that could be wind-down at 10:15 p.m. and lights out at 10:45 p.m.

Can I print my sleep schedule or put it on my phone?

Yes. Fill in your wake-up times and sleep length in the weekly sleep schedule, pick one of three designs and press Print for a one-page sheet, or Save phone wallpaper for a lock-screen image. It is saved in your browser on this device.

What does “I'm going to bed now” do?

It takes the current time, adds the time you usually need to fall asleep and shows when to set your alarm for each amount of sleep. For adults it also shows a 6-hour option, marked as below the recommended minimum, for nights that are already short.

What about 90-minute sleep cycles?

Sleep cycles average about 90 minutes but vary from roughly 70 to 120 minutes between people and through the night. That is why the calculator shows cycles as a guide and puts total hours first.

How long does it take to fall asleep?

Many healthy adults fall asleep in about 10 to 20 minutes. The calculator adds 15 minutes by default; change it if you know you usually take longer.

How can I go to bed earlier?

Move your bedtime and wake-up time 15 minutes earlier every few days, get daylight soon after waking and dim screens and lights in the last hour. The shift planner below turns that into a dated schedule.

Should I take a nap after a short night?

A short nap of 10 to 20 minutes in the early afternoon can help you through the day without making bedtime harder. The nap calculator gives you the alarm time and warns you when a nap is too close to bedtime.

Is this medical advice?

No. It is a planning tool for healthy children, teens and adults. If you snore loudly, stop breathing in your sleep, feel very sleepy during the day or cannot sleep most nights, talk to a doctor.

Sources and evidence

1. CDC: About sleep — Recommended hours of sleep per 24 hours for every age from newborns to adults 65 and older, and going to bed and getting up at the same time every day.
2. Watson et al. (2015): Recommended amount of sleep for a healthy adult (AASM and SRS consensus) — Adults should sleep 7 or more hours per night on a regular basis.
3. Hirshkowitz et al. (2015): National Sleep Foundation's sleep time duration recommendations — 7 to 9 hours recommended for adults 18 to 64, and 7 to 8 hours for adults 65 and older.
4. Paruthi et al. (2016): Recommended amount of sleep for pediatric populations (AASM consensus) — Recommended sleep per 24 hours from 4 months to 18 years, naps included up to age 5: for example 9 to 12 hours at 6 to 12 and 8 to 10 hours at 13 to 18.
5. Blume, Garbazza and Spitschan (2019): Effects of light on human circadian rhythms, sleep and mood — Morning light helps shift the body clock earlier; evening light delays it.