Bilirubin Risk Zone Calculator

About this calculator

Neonatal jaundice — yellowing of a newborn's skin from elevated bilirubin — is extremely common and usually harmless, but doctors track it against age-in-hours because bilirubin that's high too early carries more risk than the same level reached later. Clinicians traditionally plot total serum bilirubin against the baby's age in hours on a nomogram (such as the Bhutani nomogram) to sort readings into risk zones — low, low-intermediate, high-intermediate, and high risk of significant hyperbilirubinemia.

This calculator uses a simplified linear approximation of that age-versus-bilirubin relationship to estimate which risk zone a reading falls into. It illustrates how the same bilirubin number can mean different things at 12 hours old versus 72 hours old — but it is a simplified educational estimate, not medical advice, and any real newborn bilirubin concern should be evaluated by a pediatrician using the actual clinical nomogram and lab-grade testing.