Figuring out a realistic bedtime for a child is one of the most practical parts of good sleep hygiene. The Bedtime for Child Calculator works backwards from your child's usual morning wake-up time: it subtracts the recommended amount of night sleep for their age and allows for afternoon naps, so you get a clear target for when lights should go out.
Pediatric sleep guidelines from organizations such as the American Academy of Sleep Medicine and the CDC group healthy sleep needs by age, from newborns who may need up to 17 hours a day to teenagers who need 8–10 hours. This calculator turns those recommendations into a simple schedule for your family. It also shows an optimal bedtime range, not just a single number, because sleep needs vary from child to child. Use it to set a consistent routine, plan nap transitions, and make the evening wind-down calmer and more predictable.
🌙 Plan a Child-Friendly Bedtime
Child's age
Morning wake time
Daytime sleep (minutes)
Add all naps together.
Time to fall asleep (minutes)
How to Use This Tool
This calculator works backward from one anchor point: the time your child actually wakes up on most mornings. Choose the realistic wake time, not the ideal one, because children who get enough sleep tend to wake at roughly the same hour every day. Keeping this anchor consistent makes the recommended bedtime far more reliable.
- Enter the child's age in years or months. The preset buttons below the field quickly fill in common ages from 6 months to 13 years.
- Set the usual morning wake-up time. Most family routines settle somewhere between 6:00 and 8:00 AM.
- Add up all daytime sleep in minutes. For babies this means every nap across the day; for older children who no longer nap, enter 0.
- Estimate how long it typically takes from lights out to actually falling asleep. Fifteen minutes is a reasonable default for most children.
- Press Calculate Bedtime to see the recommended lights-out time, a healthy range, and a step-by-step breakdown of the math.
How the Bedtime Is Calculated
The calculator uses the age-based sleep duration recommendations published in the pediatric sleep duration consensus statement by the American Academy of Sleep Medicine, which are also reflected in guidance from the CDC and the National Sleep Foundation.
For each age group, the consensus statement gives a recommended range of total sleep per 24 hours. The calculator removes daytime naps to estimate how much of that sleep must happen at night, then subtracts the time the child needs to fall asleep:
Bedtime = wake-up time − (recommended nightly sleep + sleep-onset time)
Take a toddler who needs 11–14 hours of total sleep and naps 1.5 hours each day. That leaves roughly 9.5–12.5 hours overnight. If lights go out at 7:30 PM and the child needs 20 minutes to fall asleep, a wake-up around 6:45 AM sits comfortably inside the target range.
Worked Examples
Example 1 — Toddler with one nap. A 2-year-old wakes at 7:00 AM, naps once for 90 minutes, and takes 15 minutes to fall asleep. The toddler range is 11–14 hours total, so the night sleep target becomes 9.5–12.5 hours. Lights out should fall between about 6:30 PM and 9:15 PM, with a midpoint near 7:45 PM.
Example 2 — Preschooler who no longer naps. A 4-year-old wakes at 6:45 AM and sleeps only at night. The preschooler range is 10–13 hours. With a 15-minute sleep onset, the bedtime window runs from about 5:45 PM to 8:30 PM; a realistic midpoint for most families is around 7:00 PM, which still supports a fully rested morning.
Example 3 — School-age child. A 9-year-old wakes at 6:30 AM and needs 9–12 hours. With no nap and a 20-minute onset, lights out should land between 6:30 PM and 9:10 PM. The middle of that range, roughly 7:45 PM, usually fits best around homework and evening activities.
Sleep Needs by Age
The ranges below come from the AASM consensus statement and are built into the calculator:
| Age group | Total sleep per 24 hr | Typical daytime sleep |
|---|---|---|
| 0–3 months | 14–17 hr | 5–8 hr across several naps |
| 4–11 months | 12–15 hr | 2–4 hr across 2–3 naps |
| 1–2 years | 11–14 hr | 1.5–3 hr across 1–2 naps |
| 3–5 years | 10–13 hr | 0–1.5 hr, often one nap |
| 6–12 years | 9–12 hr | Usually none |
| 13–18 years | 8–10 hr | None |
These ranges describe total sleep per 24 hours, including naps. Within each group, the higher end usually fits younger children and the lower end fits older ones.
Common Mistakes to Avoid
- Ignoring naps. A single 1-hour nap shifts the ideal bedtime about an hour later. For children under 3, nap time is usually the difference between a 6:30 PM and an 8:00 PM lights-out.
- Basing the schedule on a weekend wake time. If weekends drift much later, the calculation produces an unrealistically late bedtime for school nights.
- Treating lights-out as the moment of sleep. Most children need 10–30 minutes of wind-down before falling asleep. Build this into the schedule so the target is not missed before the night begins.
- Expecting overnight changes. Bedtime routines take several nights to show results. Collect 4–7 days of observations before adjusting the target again.
Frequently Asked Questions
When does the bedtime clock start? Bedtime means lights out and the start of the sleep window. If the child talks or plays quietly for a while before settling, that period should be part of the routine rather than extra time added on top of the target.
What if my child wakes earlier than planned? If the child wakes more than 30 minutes early but seems refreshed, the bedtime may be slightly too early; move it 15 minutes later for a few nights. If they wake grumpy or resist waking, shift it earlier instead.
Can I use this for siblings? Yes, but the calculator recommends a time for one child at a time. Compare the suggested ranges for each sibling and pick a shared bedtime that sits inside both windows whenever possible.
Is a single fixed bedtime better than a range? Yes. The range shows what is healthy, but children thrive on consistency. Choose one time inside the range and keep it within 15 minutes on weeknights and weekends.
For more guidance, see the CDC sleep resources or the NHLBI sleep health page.