Average length of a newborn baby is 50 cm. Baby gains about 3.5
cm per month during first three month, about 2.0 cm per month during
3-6 months, about 1.5 cm per month during 6-9 months and about 1.3cm
per month during 9-12 month. Baby is about 60 cm at 3 months, 70cm at 9
months, 73 to 75 cm at 12 months thus 50 percent gain over birth length
occurs by first birthday. Your Baby’s Pediatrician will measure
your baby’s length on a machine known as Infantometer. This can
also be done in a simple way by using a measuring steel tape but
remembers to straighten well the lower limbs of the baby.