Sleep windows

Sleep windows, not sleep rules

Xoul is not a sleep coach. It doesn't tell you to let your child cry. It shows you when sleep is likely available based on your baby's own logged pattern — and what you do with that is your call.

How it works

Your logged sleep history, turned into a map

Xoul looks at the last 5–10 days of sleep entries — from all caregivers combined. It computes a weighted moving average of wake window length at different times of day. More recent days carry more weight than older ones.

The result is an estimate: "next nap probably 2:30–3:15pm." That means based on recent patterns, sleep availability is likely in that window. It is not a guarantee, not a schedule, and not a recommendation. If your baby falls asleep at 1:50pm or stays awake until 3:45pm, that's consistent with the estimate.

Xoul does not use age-based population averages. It uses your baby's own logged data — the only pattern that actually matters for your household.

Sleep window estimation chart showing wake windows and estimated sleep opportunity for a 7-month-old

"We do not tell you to let your child cry. We show you when sleep is likely available. What you do with that is entirely your call."

Data inputs

What goes into the estimate

Xoul uses only what you've logged. Nothing inferred from third-party data.

Sleep start and end times

Every sleep entry you log becomes part of the pattern. Naps and overnight sleep are tracked separately.

Wake window patterns

How long your baby has been awake since the last sleep is the primary signal for window estimation.

Recent trend weighting

More recent days are weighted more heavily. A 4-day-old entry has less influence than yesterday's pattern.

Feed timing context

Feed timing informs the wake window calculation — a large feed before sleep is a signal that may shift the window estimate slightly.

Start mapping your baby's sleep patterns

Free on iOS and Android. Two caregivers included at no charge.

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