There is no universally or even nationally agreed average weight for babies at six months of age, although most people in the know seem to put the figure at around 16lbs for girls of this age, with 14 - 21lbs being the healthy range. Boys tend to be a couple of pounds heavier but there are vast individual differences between babies as there are with adults. For most babies there is a decline in the rate of growth when they reach 6 months old, whereas previously their weight would increase by around 1.5-2lbs per month (700-900g), after 6 months the increase drops to a more moderate 1-1.25lbs per month (450-600g). This rate continues until the infant reaches the age of one year, at which point it slows slightly more.
As a rule of thumb, at four months of age most babies weigh about twice what they did at birth, and by eight months of age around 2.5 times as much. This rule highlights the importance of birth weight as a factor in the weight of a baby at 6 months old, for example a premature baby of typical low birth weight will probably still be smaller than full-term peers by 6 months. The important thing is that there is a steady increase in weight, and consistent growth trends are what doctors are interested in for assessing a baby’s health, rather than one-off measurements.
Other factors that will affect a 6 month-old’s weight include the amount and quality of food being given to her (for example, breast milk versus formula, or whether or not she’s started on solid foods yet), genes inherited from her parents, overall health and the functioning of hormones that control aspects of growth.
As a rule of thumb, at four months of age most babies weigh about twice what they did at birth, and by eight months of age around 2.5 times as much. This rule highlights the importance of birth weight as a factor in the weight of a baby at 6 months old, for example a premature baby of typical low birth weight will probably still be smaller than full-term peers by 6 months. The important thing is that there is a steady increase in weight, and consistent growth trends are what doctors are interested in for assessing a baby’s health, rather than one-off measurements.
Other factors that will affect a 6 month-old’s weight include the amount and quality of food being given to her (for example, breast milk versus formula, or whether or not she’s started on solid foods yet), genes inherited from her parents, overall health and the functioning of hormones that control aspects of growth.
