What if my baby won't nap as long as the schedule suggests?

Short naps are common and point to no single cause. Look at the wider pattern — mood, settling, total sleep and whether it repeats. Change one small thing (about 10–15 minutes of wake window) and reassess over several days.

My baby's wake-up time varies — is the schedule useless?

No. The calculator recalculates from whatever wake time you enter. Treat an earlier or later start as a fresh sample day rather than something to follow exactly.

When should we start a sleep schedule?

Most guidance suggests waiting until around 8–12 weeks before adding any structure: newborns feed on demand and their day-night rhythm is not yet developed. A steadier schedule typically becomes possible around 4–5 months.

What is a split night?

A long stretch awake in the middle of the night. Too much daytime sleep or a schedule that no longer fits can contribute, but night waking has many causes. Watch the pattern across several days and make one modest adjustment at a time.

Is it normal for sleep to get worse around 4 months?

Many families notice sleep changing around 3–5 months as infant sleep cycles become more adult-like. It is a normal developmental change, not a diagnosis, and timing varies. A hard week does not automatically mean lengthening wake windows.

Should I wake my newborn to feed?

Usually no. The AAP notes that healthy, growing babies generally do not need to be woken to breastfeed. Follow your pediatrician's guidance, especially for very young, small, or slow-gaining newborns.

Is it safe for my baby to sleep in my bed?

The AAP recommends room-sharing with your baby in their own crib rather than bed-sharing. A firm, flat, separate sleep surface in the same room is recommended for at least the first 6 months.

SLEEP SCHEDULE

Build your baby's sample sleep day

Enter your baby's age and your usual morning wake-up time. The calculator builds an illustrative sample day with nap timings, wake-window estimates, 24-hour sleep context and a suggested bedtime range.

Last reviewed: 2026-10-15

Guidance only: This calculator creates a planning example, not a prescription. The AAP, CDC and WHO describe wide variation in infant sleep and publish no official wake-window schedule. Wake-window values below are planning estimates; 24-hour sleep ranges come from the cited guidance. If you have concerns about sleep, breathing, feeding or development, speak to your pediatrician.

Your sample day

For a baby 4 months old, waking at 07:00

24-hour sleep: 12–16 h
Naps per day: 3–4
Wake window: 1.3 h – 2 h (estimate)
Suggested bedtime: 19:30–20:30

Your day at a glance

07:00Wake up
08:42Nap 1
12:18Nap 2
15:54Nap 3
20:00Bedtime

AwakeNapSuggested bedtime

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Watch for overtiredness cues. Yawning, eye rubbing, staring into space and fussiness are all signs your baby needs sleep. Always respond to tired signs rather than watching the clock rigidly — these schedules are guides, not rules.

Sleep needs by age

Age	Wake window	Naps per day	Total per 24 hours	Source
0 to 6 weeks	35 min – 1 h (estimate)	5–6	14–17 h	[1] [3]
7 to 12 weeks	1 h – 1.5 h (estimate)	4–5	14–17 h	[1] [3]
3 to 4 months	1.3 h – 2 h (estimate)	3–4	12–16 h	[1] [2]
5 to 6 months	2 h – 2.5 h (estimate)	3–3	12–16 h	[1] [2]
7 to 9 months	2.5 h – 3 h (estimate)	2–3	12–16 h	[1] [2]
10 to 12 months	3 h – 4 h (estimate)	2–2	12–16 h	[1] [2]
13 to 18 months	4 h – 5 h (estimate)	1–2	11–14 h	[1] [2]
19 to 24 months	5 h – 6 h (estimate)	1–1	11–14 h	[1] [2]

Wake window: planning estimate — no official table exists.

How this is calculated

The tool looks up your baby's age band for the 24-hour total (stated by the CDC and the AASM consensus endorsed by the AAP) and for the wake-window range and typical nap count (planning estimates, no official table). It then walks forward from your wake-up time, alternating wake windows and typical naps, and lands on a bedtime with a ±30 minute range. Structured mode rounds every clock time to the nearest 15 minutes.

About wake windows. A wake window is the time a baby can comfortably stay awake between sleeps. Awake periods lengthen with age, but no single timing fits every baby. First windows run shortest, last windows often longest. These values are editorial planning estimates used to build a sample day.

The last wake window is not a rule. Some babies manage a longer stretch before bed and some do not, especially after short naps, illness or a busy day. The final window here is part of the sample model, not a requirement and no guarantee of better night sleep.

Schedules are guides, not rules. Illness, teething, feeding changes, travel and development can all move sleep around. Use this as a flexible framework and look at the wider pattern across several days rather than forcing every nap onto the clock.

Nap transitions are the hardest part. Dropping from 3 naps to 2, or 2 to 1, can make a workable day look broken for a while. The ages here are planning bands, not deadlines. Look for a repeated pattern across several days before changing the whole schedule. [3]

Questions

What if my baby won't nap as long as the schedule suggests?: Short naps are common and point to no single cause. Look at the wider pattern — mood, settling, total sleep and whether it repeats. Change one small thing (about 10–15 minutes of wake window) and reassess over several days.
My baby's wake-up time varies — is the schedule useless?: No. The calculator recalculates from whatever wake time you enter. Treat an earlier or later start as a fresh sample day rather than something to follow exactly.
When should we start a sleep schedule?: Most guidance suggests waiting until around 8–12 weeks before adding any structure: newborns feed on demand and their day-night rhythm is not yet developed. A steadier schedule typically becomes possible around 4–5 months.
What is a split night?: A long stretch awake in the middle of the night. Too much daytime sleep or a schedule that no longer fits can contribute, but night waking has many causes. Watch the pattern across several days and make one modest adjustment at a time.
Is it normal for sleep to get worse around 4 months?: Many families notice sleep changing around 3–5 months as infant sleep cycles become more adult-like. It is a normal developmental change, not a diagnosis, and timing varies. A hard week does not automatically mean lengthening wake windows.
Should I wake my newborn to feed?: Usually no. The AAP notes that healthy, growing babies generally do not need to be woken to breastfeed. Follow your pediatrician's guidance, especially for very young, small, or slow-gaining newborns.
Is it safe for my baby to sleep in my bed?: The AAP recommends room-sharing with your baby in their own crib rather than bed-sharing. A firm, flat, separate sleep surface in the same room is recommended for at least the first 6 months.

Keep reading

Track it in the app, not on a calculator

This is a planning range. The number that matters is what your baby actually takes. Log a feed in one tap and see today's total without adding anything up.

Features

✓One tap to log a feed
✓Today's total, automatic
✓Share with the other caregiver

Sources

[1]CDC, "About Sleep," reviewed May, 2024. cdc.gov ↗
[2]AASM (endorsed by AAP), "Recommended Amount of Sleep for Pediatric Populations: A Consensus Statement," reviewed June 13, 2016. aasm.org ↗
[3]Stanford Medicine Children's Health, "Infant Sleep," reviewed 2024. stanfordchildrens.org ↗

Accessed: 2026-10-15.

A planning estimate, not medical advice

This tool applies published guidance to the numbers you enter. Every baby is different. Use the result as a starting point and follow your pediatrician's advice for your baby.