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Sleep Window Calculator

Rest is the invisible foundation of childhood growth. Without it, everything else—learning, emotional regulation, creativity—becomes an uphill battle. Find a mathematically sound, realistic sleep window to protect their most vital recovery time.

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How much sleep does my child need by age?

Pediatric sleep guidelines are consistent: preschoolers (3–5) need 10–13 hours per 24 hours, school-age children (6–12) need 9–12 hours, and teenagers need 8–10 hours. Yet most families plan bedtime from the evening forward — when the math actually runs backward from the morning alarm.

That's why the same 9pm bedtime can be fine for one child and chronically short for another: the wake-up time sets the window. A child who must be up at 6:30am for school needs lights-out meaningfully earlier than a child who wakes at 7:45am, even at the same age.

The Sleep Window Calculator does that backward math for you: enter your child's age band and required wake time, and it returns a realistic target bedtime and total sleep window — the invisible foundation under learning, mood, and growth.

Common Questions

What time should my child go to bed?
Work backward from wake-up time. Take the recommended sleep for their age (10–13h for ages 3–5, 9–12h for 6–12, 8–10h for teens), subtract from the alarm time, and add 15–30 minutes for falling asleep. That's the lights-out target.
How do I know if my child is getting enough sleep?
Reliable signs of a short sleep window: hard to wake on school days but sleeping in hours later on weekends, afternoon meltdowns or fog, and falling asleep instantly (under 5 minutes). Weekend catch-up sleep of 2+ hours usually means the weekday window is too small.
Do screens really affect kids' sleep?
Yes, through two paths: light exposure delays melatonin, and stimulating content keeps the brain alert. A screens-off buffer of 30–60 minutes before the target bedtime protects the window you calculated.

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