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Bedtime calculator by age

Enter a wake-up time and an age, and get the latest bedtime that still fits the recommended hours of sleep.

Runs in your browser. Nothing is sent or saved.By Nabeel MustafaUpdated
min

Change it if you know you take longer to drop off.

Go to bed by

23:45

For 7 hours of sleep, the least the CDC lists for this age. More is fine.

Bedtime for each amount of sleep

  • 7 hours23:45
  • 8 hours22:45
  • 9 hours21:45

Formula and sources

Bedtime = wake-up time minus the hours of sleep recommended for the age, minus the time it takes to fall asleep. For ages up to 5, where the total includes naps, daytime nap hours are taken off first. The hours by age are the CDC's, which draw on the American Academy of Sleep Medicine and the National Sleep Foundation.

A timer runs the session. Whether the sessions happen most days is a different record: a free habit tracker that shows today, the month and the year.

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A father leaning over his daughter, asleep in bed with a book beside her, in a softly lit bedroom

How the bedtime is worked out

Start from the time you have to be up, take off the hours of sleep recommended for the age, then take off the time it takes to fall asleep. What is left is the latest bedtime that still gets the full amount. A school-age child who wakes at 7:00 and needs at least 9 hours, with 15 minutes to drop off, should be in bed by 9:45.

The page shows the latest bedtime first because that is the one people miss. Going to bed earlier is fine up to the top of the range; past it, more time in bed usually means more time lying awake.

Recommended hours of sleep by age

These are the CDC's figures, which come from consensus statements by the American Academy of Sleep Medicine (children and teens) and the National Sleep Foundation and AASM with the Sleep Research Society (adults). For children up to 5, the total includes daytime naps.

  • Newborn, 0 to 3 months: 14 to 17 hours
  • Infant, 4 to 12 months: 12 to 16 hours, including naps
  • Toddler, 1 to 2 years: 11 to 14 hours, including naps
  • Preschool, 3 to 5 years: 10 to 13 hours, including naps
  • School age, 6 to 12 years: 9 to 12 hours
  • Teen, 13 to 17 years: 8 to 10 hours
  • Adult, 18 to 60 years: 7 or more hours
  • Adult, 61 to 64 years: 7 to 9 hours
  • Adult, 65 and older: 7 to 8 hours

Naps change a young child's bedtime

Because the totals for babies, toddlers and preschoolers count naps, a two-hour afternoon nap leaves two fewer hours to fit into the night. Enter the day's nap time and the calculator takes it off before working back from the wake-up time.

Newborns are left out on purpose. At that age sleep comes in short stretches around the clock, and a fixed bedtime is not something the guidance sets.

Bedtime calculator or sleep cycle calculator?

This page answers how much sleep an age needs and therefore when bed should be. The sleep calculator answers a different question: when to wake so you surface between 90-minute cycles. Use this one to set the amount, then the cycle calculator if you want to fine-tune the alarm.

Either way, the same bedtime every night does more than any calculation. A bedtime that holds on weekends is the hard part, and it is worth tracking as a habit of its own.

How to use the bedtime calculator

  1. Pick the age

    Choose the age group of the person going to bed. Each group has its own recommended hours.

  2. Enter the wake-up time

    The time the alarm goes off, or the time a child usually wakes.

  3. Set the time to fall asleep

    Fifteen minutes is the default. Raise it if falling asleep takes longer.

  4. Add naps for young children

    For ages up to 5, enter the day's total nap time. It comes off the night.

  5. Read the latest bedtime

    That is the last time to be in bed and still get the minimum. The list shows a bedtime for each extra hour.

Questions people ask

What time should I go to bed if I wake up at 6am?

For an adult who needs at least 7 hours and takes 15 minutes to fall asleep, the latest bedtime is 10:45 p.m. For 8 hours it is 9:45 p.m. Change the age and the time to fall asleep above to see your own times.

What time should a 10-year-old go to bed?

Children aged 6 to 12 need 9 to 12 hours, according to the CDC. A child who wakes at 7:00 and takes 15 minutes to fall asleep should be in bed between 6:45 and 9:45 p.m., with 9:45 the latest that still gives 9 hours.

How much sleep does a teenager need?

Teens aged 13 to 17 need 8 to 10 hours a night, according to the CDC's figures, which come from the American Academy of Sleep Medicine. A teen up at 6:30 a.m. needs to be asleep by 10:30 p.m. to get 8 hours.

Do naps count toward a child's sleep?

For babies, toddlers and preschoolers, yes: the recommended totals include naps. From age 6 the figures are for night sleep. Enter nap time in the calculator for a young child and it is taken off the night.

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