Baby and child
Baby and child tools plus sleep and growth guides. Each calculator links to its methodology and source notes.
Tools
Guides
Baby Percentile Explained
ArticleHow growth percentiles are calculated and why a single number is not a verdict.
OpenSleep Regressions by Month
ArticleWhat sleep regressions are, what triggers them, and what actually helps.
Open4 Month Sleep Regression
ArticleHow sleep architecture changes around 4 months and what helps.
Open8 Month Sleep Regression
ArticleSeparation anxiety, motor milestones, and second-half-of-year sleep changes.
Open