How Much Sleep Does My Baby Need?

A wake window is the maximum time your baby can comfortably stay awake before needing to sleep again. Getting wake windows right is the single most impactful lever you have over nap quality and night sleep. Extending too far past the wake window leads to overtiredness - which paradoxically makes falling asleep harder, not easier, because cortisol floods the system. The Nap Tracker uses your baby's age and wake time to calculate wake window boundaries and output a full day schedule.

Newborn sleep is chaotic by design. Babies this age have no circadian rhythm and cannot distinguish day from night - that develops between 6 and 12 weeks. They need 16–18 hours total across 24 hours, split across 4–5 naps with wake windows of just 45–60 minutes. There is no schedule to impose; you are simply watching for sleepy cues and responding.

The most important things at this stage are not sleep training or scheduling but establishing safe sleep practices: back to sleep, firm flat surface, room-sharing without bed-sharing, no loose bedding. These apply to every nap and every night sleep.

Around 3–4 months, the brain undergoes a permanent restructuring of sleep architecture - babies begin cycling through sleep stages like adults do, which means they fully rouse between sleep cycles every 45–50 minutes. This is what drives the infamous 4-month sleep regression. Any gains made in the first few months may temporarily disappear.

At this age, babies move to a 3-nap schedule. Wake windows expand to 1.5–2 hours. This is the earliest point at which gentle sleep training methods such as drowsy-but-awake placement and fading can begin. Most paediatricians recommend waiting until at least 4–6 months corrected age before formal training.

From around 6–8 months, most babies drop the third catnap and consolidate to two solid naps. Wake windows expand significantly - by 9–12 months, babies can comfortably stay awake for 3–4 hours between sleeps. This is the period when most babies become physiologically capable of sleeping through the night without a feed, though many still wake due to habit, association, or developmental leaps.

The 8–10 month sleep regression hits during this period, driven by object permanence development (babies now understand that you still exist when you leave the room and will protest accordingly) and the rapid motor milestones of crawling, pulling to stand, and cruising. Night waking can increase significantly even in babies who had been sleeping well.

This is the most popular age for formal sleep training. All methods - Ferber, extinction, chair method, Pick Up Put Down - are considered appropriate from 6 months by the American Academy of Pediatrics.

The shift from two naps to one is one of the trickiest transitions parents face - typically happening anywhere from 12 to 18 months. Unlike nap transitions in infancy, the 2-to-1 nap shift takes weeks to settle, and babies are often in a miserable "too tired for two naps but too young for one" limbo. The 12-month and 18-month regressions often coincide with this window, making it feel even more chaotic than it is.

Once on a single nap, toddlers need that midday sleep to last 1.5–2 hours. If the nap is too short or drops too early, night waking and early rising often worsen. An earlier bedtime (6:30–7pm) during the transition period is protective. The 1-nap sample schedule shows a Singapore-appropriate daily routine for this age.