The ideal weight of children can only be calculated based on their age and height. Find out with us how to do this calculation and consult the tables of values for boys and girls to get your bearings.
The ideal weight of children is not an indication of absolute value. Indeed, to calculate it, one must always take into account several factors such as age and height. The growth of a child in the first years of life is very important and is closely related to physical activity and healthy eating.
In order for your child to grow up healthy, it is good to know what his ideal weight should be, to learn how to calculate the body mass index, and to know how to read charts with growth percentiles. Obviously, to monitor the ideal weight of a child – since there are no absolute laws – it is always good to consult your pediatrician.
Let's try together to understand how the ideal weight of children is calculated, what it should be according to the tables of the World Health Organization (WHO) and how to calculate the percentiles of growth.
See also: 10 little joys of pregnancy
<! –
->
How do you calculate the ideal weight for children?
Again, the ideal weight for children is not a single absolute value, but only a general guideline. Rather, what is commonly referred to as the ideal or healthy weight for children is a range of values that indicate what normal weight should be at a given age. So don't panic if your child's weight is not exactly that indicated!
The different parameters to take into account when calculating the ideal weight of a child are height and, from two years old, the body mass index (also called BMI). To calculate the body mass index, it is enough to divide the child's weight (expressed in kilograms) by his height (in square meters).
From these data, it is possible to calculate the growth percentile, that is to say a reference scale of the parameters considered "normal" which is based on the growth curves generated by the observation of the population. from birth to 20 years old. Reading the percentile tables is not easy: in the following paragraphs, we will explain how to do this.
Ideal weight of children at birth and in the first months of life
A baby should have a birth weight of around 3200-3400 grams, but can be considered “normal weight” if they weigh between 2500 and 4500 grams. If the newborn baby's weight is less than 2500 grams it is considered to be underweight, if it is over 4500 grams it is considered to be a “fat baby”, overweight.
As paradoxical as it may seem, during the first days of life, an infant's weight tends to decrease by 5-7%, but – if well nourished – he regains the weight lost at the age of 15. days. From this moment until the sixth month, the weight will tend to increase by about 150 grams per week. Therefore, by the age of five months, his weight should be double that of his birth weight.
Ideal weight for children up to 10 years
From the age of one, the ideal weight for a child is about three times its birth weight. Nevertheless, from 18 months, weight gain begins to slow down, with a normal physiological stop which should not frighten the parent.
Between the age of two (when the weight is four times that of birth) and the age of five, the child's weight increases by just under 2 kg per year, while from the age of five, the growth rate begins to increase gradually, by around 2.4 kg per year until puberty.
Height and weight do not always increase evenly, which can lead – around the age of 6 – to an increase in body mass index (which, as we have said, depends on the ratio of weight and height).
Ideal weight tables for girls and boys
In the tables below, we indicate, for information only, the range of values of the ideal weight of boys and girls in relation to age and with relative indications of height. As we have already said, these are not absolute values and, in order to assess the health condition and the steady growth rate of your child, it is always a good idea to speak to your pediatrician, who will take into account your specific case.
Percentiles of growth given by the ratio between weight and height
To calculate the ideal weight of a child, we use the percentile which, as explained above, serves as a reference scale to establish the parameters of the weight to be considered normal. From the WHO website, you can download and consult the tables with the growth percentiles established by the organization.
If your child's body mass index is below the fifth percentile of the scale, he is considered to be at normal weight. If the body mass index value is between the 85th and 95th percentile, the child will be overweight, while if it exceeds the 95th percentile, it is obesity.
To simplify the consultation of the growth percentiles, even if the results are less precise, the value of the 50th percentile for the height age (age + height) is generally used. However, in these calculations it is always better to be helped by the pediatrician.