Newborn Weight Loss Calculator
Calculate percentage of weight loss in newborns and assess if it's within normal limits
About this calculator
The Newborn Weight Loss Calculator helps parents and healthcare providers monitor infant weight changes during the critical first days of life. It calculates the percentage of weight loss from birth weight and indicates whether the loss falls within normal medical guidelines. Most newborns lose 5-10% of their birth weight in the first week, and this calculator provides peace of mind by clearly showing if weight loss is typical or requires medical attention.
How to use
Enter your baby's birth weight and current weight in the same units (pounds or kilograms). The calculator will automatically compute the percentage of weight loss and indicate if it's within the normal range of 5-10% or if you should consult your pediatrician for weights outside this range.
Frequently asked questions
What's considered normal newborn weight loss?
Normal weight loss is 5-10% of birth weight within the first week. Most babies regain birth weight by 2-3 weeks old.
When should I be concerned about weight loss?
Contact your pediatrician if weight loss exceeds 10% of birth weight or if baby hasn't regained birth weight by 3 weeks.
Why do newborns lose weight after birth?
Weight loss occurs due to fluid loss, meconium passage, and initial feeding adjustments as babies learn to breastfeed or bottle-feed effectively.