Postnatal Height & Weight Development

Growth is complex. It depends on a whole number of interacting factors, such as the amount and quality of food, genetics, whether the child's various organ systems are functioning well, the adequacy of the hormones controlling aspects of growth, a child's emotional well-being and environment.

Babies grow at their own rate and the figures below are meant only to serve as an indication.
For the main milestones in this area, and other main developmental areas, go here .

If you are concerned about your baby's weight or growth in general, discuss your worries with your child's doctor.

Neonate

The majority of babies born full-term , i.e. 40 weeks, weigh from just over 2.6 to 3.8 kilos (5 lb, 11 oz to almost 8 LB, 6 oz), and they are between 48 - 53cm (19 and 21 inches) long.
Certain factors can affect a baby's size at birth.

A newborn will gain weight at a rate of approximately 19 gm (2/3 oz) per day and grow about 2.5 - 4cm (1 - 1½ inches) during the first month. Most newborns go through a period of rapid growth (a growth spurt) when they are 7 to 10 days old and again between 3 and 6 weeks.

First 3 Months

After losing some of their birth weight during the first few days of life, most babies will then continue to grow steadily. By the middle of the first month, weight gain should be about 14-28gm (½ - 1oz) per day. This increases to, on average, 0.45 - 0.9kg(1½ - 2 pounds) following the first month.

Increases in length during this same period may be about 2.5 - 3.7cm (1 - 1½ inches) per month.

4-7 Months

It is usually during this period that solid foods are introduced into the babies diet.
The average rate of growth for a baby between 4 and 7 months old is about 0.4 - 0.5kg (1 to 1.25lb) a month. By 8 months your baby will probably weigh about 2½ times birth weight. However, this varies from one baby to another.
Tremendous bone growth means length will also increase greatly, perhaps 5cm/2 inches during this period.

8-12 Months

The variables affecting growth, especially weight, in this period are many. For example, most babies now move around on their own, and are showing increasing proficiency at handling solid foods.
By 8 months of age, most babies weigh around 6.3 - 8.1kg (14 to 18lb), although the range of normal is wider than that. After the first 12 months of life, most babies will probably have just about tripled (3x) their birth weight and will probably stand about 70-80cm (28 to 32 inches) tall.

1-2 Years

During the 2nd year of life, increases in weight decrease with most babies gaining between 1.4 - 2.3kg (3 - 5lb). By their second birthdays, most are losing that baby look and growing taller instead of rounder.
While developmental growth is still going full speed ahead, physical growth slows down during this year. Changes during this period are related more to the baby's appearance than actual growth. For example, instead of the rounded belly and soft arms and legs suited to crawling on all fours, during this second year the toddler will most likely trim down, becoming more muscular due to increased activity.