Infant Calorie Needs

About this calculator

Infants need far more energy per kilogram of body weight than adults — roughly 100-110 kcal/kg/day in the first six months, gradually declining toward 80-100 kcal/kg/day by age one, because a large share of their intake fuels rapid growth rather than just maintaining existing tissue. This is why calorie needs are calculated per kilogram rather than as a flat number: a 4 kg newborn and a 9 kg nine-month-old have very different absolute requirements even though the per-kilogram rate is similar.

Pediatricians and lactation consultants use this kind of weight-based estimate when checking whether a baby's intake from breast milk or formula (typically providing about 20 kcal per fluid ounce) lines up with expected needs, especially when tracking growth for premature infants or babies who are gaining weight slowly. It is a starting reference point, not a substitute for a pediatrician's individualized growth-chart assessment.

This calculator takes a baby's body weight and returns an estimated daily calorie need.