Child Sleep Calculator: Recommended Bedtime by Age

Parents often ask how much sleep a young child should get, and the answer depends on age, school schedule, and bedtime routine length. This child sleep calculator uses pediatric guidelines (AAP and AASM) to recommend a target bedtime and total sleep window. For example, a 5-year-old who wakes at 6:45 AM and needs 11 hours of sleep should be asleep by 7:45 PM, which means starting a 30-minute routine around 7:15 PM. Adjust inputs to model toddlers (11–14 hours) through school-age kids (9–12 hours).

The tool converts the recommended sleep duration into a concrete schedule you can follow on weeknights. If your 5-year-old wakes at 7:00 AM and you target 10.5 hours of sleep, asleep-by time becomes 8:30 PM, and a 45-minute wind-down begins at 7:45 PM. The headline numbers in the keyword (such as ‘5-year-old’ or ‘11 hours’) are only example defaults; the calculator works for any age between 1 and 12 and any wake time. Use it to plan consistent weeknight bedtimes that protect cognitive performance, mood, and growth.

How it works: Enter your child’s age, wake-up time, and bedtime routine length. The calculator picks an age-appropriate sleep target, subtracts it from wake time to find asleep-by time, then subtracts the routine to recommend a start-routine time.

How Much Sleep Children Need by Age (2026 Pediatric Guidelines)

Sleep needs change rapidly through childhood. Use the table below as your baseline, then personalize with the calculator above based on your child’s wake time, naps, and activity level.

Recommended sleep per 24 hours by age (AAP & AASM, 2026)

Sample 5-year-old schedules by wake-up time

Why 5-year-olds specifically need 10–13 hours

The American Academy of Pediatrics and the American Academy of Sleep Medicine recommend 10–13 hours of sleep per 24 hours for children ages 3–5. By age 5, most kids have dropped daytime naps, so nearly all of that sleep happens at night. Rule of thumb: a 5-year-old who is hard to wake before school is undersleeping by at least 30–60 minutes. Chronic shortfalls under 9.5 hours are linked to attention problems, emotional dysregulation, and lower academic performance in kindergarten and first grade.

Wake-up time anchors everything

Sleep schedules should be built backward from the wake-up time, not forward from a desired bedtime. School start at 8:15 AM with a 45-minute morning routine means waking at 7:00 AM at the latest. Subtract 11 hours and your 5-year-old must be fully asleep by 8:00 PM. A common parenting mistake is to start bedtime at the asleep-by time; instead, start the wind-down 20–45 minutes earlier. Aim for lights-out within 15 minutes of getting into bed; longer than that suggests bedtime is too late or screen time is too close.

The 20–45 minute bedtime routine sweet spot

Routines that are too short (under 15 minutes) skip the parasympathetic wind-down; routines over 60 minutes create stalling opportunities and shift bedtime later. A solid framework: 10 minutes bath or wash, 10 minutes pajamas plus teeth, 10 minutes book in bed, 5 minutes cuddle and lights out. Rule of thumb: same order every night, same room, dim lights below 50 lux after routine starts. Consistency in sequence matters more than fancy content—predictability is what cues melatonin release.

Naps after age 3: when to drop them

By age 5, only about 25–30% of children still nap regularly. If your child naps 60+ minutes after 3 PM and then resists bedtime past 9 PM, the nap is the problem, not bedtime resistance. Common guideline: total sleep matters more than nap-versus-night sleep, so subtract any nap from the nighttime target. A 1-hour nap on a 5-year-old who needs 11 hours leaves 10 hours of night sleep. If naps no longer happen, reset bedtime 30–60 minutes earlier to compensate.

Screens, melatonin, and the 60-minute rule

Blue-spectrum light from tablets and TVs suppresses melatonin by 20–50% in school-age children, delaying sleep onset by an average of 30 minutes. Common guideline: no screens within 60 minutes of asleep-by time. A 5-year-old asleep by 8:00 PM should be screen-free from 7:00 PM. Replace screens with audiobooks, drawing, or board games. Also avoid sugar and rough-and-tumble play within the last hour. A dim, cool (65–70°F / 18–21°C), quiet room cuts sleep latency to under 15 minutes for most children.

Weekend drift and social jet lag

Letting bedtime slide by 90+ minutes on Friday and Saturday creates ‘social jet lag’—your child’s body clock is on a different time zone Monday morning. Rule of thumb: keep weekend bedtime within 30–60 minutes of the weeknight schedule, and wake-up time within 60 minutes. If your 5-year-old goes to bed at 7:45 PM weeknights, weekend bedtime should be no later than 8:45 PM. Catching up on sleep with weekend marathons is partially effective but doesn’t reverse the cognitive deficits of chronic weeknight shortfalls.

Signs your child is undersleeping

Look for these markers: difficulty waking after 11+ hours in bed, falling asleep within 2 minutes of car rides under 10 minutes, increased meltdowns between 4–6 PM, and reduced appetite at breakfast. One concrete test: on a school morning, does your child wake spontaneously before the alarm? If not for 5+ consecutive days, shift bedtime 15 minutes earlier each week until they do. Most parents underestimate their child’s sleep need by 30–60 minutes per night.

How This Calculator Works: Methodology & Parameter Explanations

Core formula: Step 1: pick age range (1–2y: 11–14h, 3–5y: 10–13h, 6–12y: 9–12h). Step 2: target = midpoint adjusted by sleep_need_preference (low/mid/high). Step 3: night_sleep = target − nap_hours. Step 4: asleep_by = wake_up_time − night_sleep. Step 5: start_routine = asleep_by − (bedtime_routine_length / 60). Times wrap on 24-hour clock.

Parameter explanations

Assumptions

Sleep ranges follow 2026 AAP and AASM consensus guidelines for healthy children without medical sleep disorders.

The age ‘5 years old’ in the keyword is an example default; the calculator works for any age from 1 to 12.

Asleep-by time refers to actual sleep onset, not when the child enters the bedroom. Lights-out should be ~10 minutes earlier.

Schedule assumes a single nighttime sleep period; split sleep, shift-working parents, and infants under 1 are out of scope.

Routine length and nap hours are converted to hours internally; outputs are rounded to the nearest minute.

Parameter meanings