Calculators for pregnancy and the early years
They all run in your browser, sending nothing anywhere, and they all explain where their result comes from. None replaces your paediatrician: they are for understanding better what you are already told.
Pick one
- Adult height predictorHow tall your child will be, based on their parents' height
- The genetic lottery: eye colourWhich eye colours are on the table given the parents', and why there is no exact percentage
- Blood ties: your baby's possible blood typeWhich ABO and Rh types your child can have, and which combinations are impossible
- Weight and head circumference percentile (0-5 years)Where your baby sits on the official WHO growth charts
- Children's BMI (ages 2 to 18)A child's body mass index does not read the same way as an adult's
- Corrected age for premature babiesThe age to use to properly read their percentiles and milestones
- The odds of having twins: the real factorsWhat actually raises the odds of a multiple pregnancy, and what is a myth
Each calculator carries an article below it with the formula it uses, its real margin of error and the sources cited. If a figure has no backing, it does not appear.