Child Sleep Requirements Calculator
Calculate how many hours your child should sleep and what bedtime to set, based on age, activity level, and school schedule. Enter a desired wake time to get a specific, personalized bedtime recommendation.
About this calculator
Sleep needs decrease progressively from infancy through adolescence. This calculator starts with evidence-based baseline hours: ~14 h for infants under 1, 12.5 h for toddlers (1–2), 11.5 h for preschoolers (3–5), 10 h for school-age children (6–12), and 9 h for teenagers. An activity adjustment adds up to 1 hour for highly active infants or 0.5 h for active older children, and subtracts 0.5 h for low activity. A schedule adjustment removes 0.5 h on weekends and 1 h in summer, reflecting natural sleep shifts. Total sleep hours are then converted to minutes: bedtimeMinutes = totalHours × 60. Bedtime = wakeTime − totalSleepMinutes, wrapped to a 24-hour clock. The formula reflects American Academy of Pediatrics (AAP) and National Sleep Foundation recommendations.
How to use
Example: A 7-year-old with high activity level on a school day who needs to wake at 7:00 AM (wakeTime = 700). Step 1: baseHours = 10 (age 6–12). Step 2: activityAdjust = +0.5 (high activity, age ≥ 1). Step 3: scheduleAdjust = 0 (school day). Step 4: totalHours = 10 + 0.5 = 10.5 h = 630 minutes. Step 5: wakeTimeMinutes = 7 × 60 + 0 = 420. Step 6: bedtime = (420 − 630 + 1440) % 1440 = 1230 minutes = 20:30, i.e., 8:30 PM. This child should be in bed by 8:30 PM to get the recommended 10.5 hours of sleep.
Frequently asked questions
How many hours of sleep does a school-age child actually need per night?
The American Academy of Pediatrics recommends 9–12 hours per night for children ages 6–12, and the National Sleep Foundation narrows this to 9–11 hours for the same age group. The exact amount varies by individual — some children function well at the lower end while others need the full 12 hours. Signs of insufficient sleep include difficulty waking in the morning, irritability, trouble concentrating at school, and falling asleep within minutes of lying down. Consistently getting less than the recommended amount is associated with increased risk of obesity, impaired immune function, and behavioral problems.
Why do teenagers need less sleep than younger children but more than adults?
Adolescents (ages 13–18) need 8–10 hours per night according to the AAP, which is less than younger children but still substantially more than the 7–9 hours recommended for adults. This elevated need is driven by rapid brain development, hormonal changes, and increased physical growth during puberty. Additionally, puberty shifts the circadian rhythm later — a biological process called sleep phase delay — making it genuinely harder for teens to fall asleep before 11 PM and wake early. This is why many pediatric sleep researchers and the AAP advocate for middle and high school start times no earlier than 8:30 AM.
What is the best bedtime routine to help a child fall asleep faster?
A consistent pre-sleep routine signals the brain that sleep is approaching and can reduce sleep onset time by 15–30 minutes in young children. Effective routines typically last 20–45 minutes and include a warm bath or shower, brushing teeth, quiet reading or storytelling, and dimming lights. Screens — phones, tablets, televisions — should be turned off at least 60 minutes before bedtime because blue light suppresses melatonin secretion. The routine should start at the same time every night, including weekends; even a 30-minute variation in bedtime on weekends can cause social jet lag, making Monday mornings harder. Keeping the sleep environment cool (65–68°F), dark, and quiet further improves sleep quality.