Free Tools

Quick, free and interactive: the calculators parents actually reach for, built on the same public data our guides cite. No sign-up, no paywall.

Baby Wake Window Calculator

How long should your baby stay awake between naps? Get the typical wake window for their age and the time range the next nap is likely to land in.

See where your baby's weight or length lands on the official WHO growth standards, with the median for their age and what percentiles actually mean.

Estimate your due date from your last period with cycle-length adjustment, and see how many weeks along you are today.