0 to 3 months

Newborns sleep 14 to 17 hours across a 24-hour cycle, in short stretches of two to four hours at a time. Day and night look similar. Wake windows are 45 to 60 minutes. Try not to keep your baby up beyond that — overtired is the single biggest cause of difficult settling.

3 to 6 months

Total sleep settles into 12 to 15 hours. Longer night stretches appear, often 5 to 7 hours by the end of this window. Wake windows grow to 90 to 120 minutes. Most babies move to three naps a day, though the third nap is often short and unpredictable.

6 to 9 months

Total sleep is 11 to 14 hours. Wake windows lengthen to two to three hours. Two longer naps replace the earlier three. Night feeds are usually down to one or none, depending on weight and feeding pattern.

9 to 12 months

Most babies consolidate into two naps a day and 10 to 12 hours at night. Wake windows of three to four hours are typical. A short period of separation-anxiety night waking is normal around 9 months — it passes within a few weeks.

Sleep regressions

The four-month regression is the most discussed. It is not a regression but a reorganisation — sleep cycles mature into a more adult-like structure with lighter stages between deep sleep. The eight-month and twelve-month bumps are smaller and tied to developmental leaps.

What to track

Wake windows are the single most useful metric. They predict the next nap better than the clock. One Baby’s sleep prediction feature uses your own logs alongside paediatric norms to estimate the next nap within minutes of when your baby is likely to need it. Most parents tell us the prediction is the feature that surprised them most.

When to call the doctor

Sudden, sustained sleep changes that do not match a known regression — paired with feeding changes, fever, or unusual mood — are worth a call to your paediatrician. Trust your instinct.