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.
Open the tool →Baby Growth Percentile Calculator
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.
Open the tool →Baby Growth Chart (WHO)
The WHO growth curves for weight and length, boys and girls, 0 to 24 months, drawn from the official standards rather than reproduced as a picture.
Open the tool →Pregnancy Weight Gain Calculator
Recommended total weight gain for your pregnancy from your pre-pregnancy BMI, on the Institute of Medicine ranges the CDC publishes, for one baby or twins.
Open the tool →Pregnancy Due Date Calculator
Estimate your due date from your last period with cycle-length adjustment, and see how many weeks along you are today.
Open the tool →