n Paediatrics, we use different formula to roughly access whether a child's weight is normal for age. I see no reason why all parents shouldn't be armed with this information as well.

So let's begin. Things you would need for this are a weighing scale and perhaps a calculator. To learn how to weigh your child, you can refer to my earlier post on this.

So for children that are 1 year and below (infants), we use this formula

(n + 9) /2

The n is in months and the weight gotten is in kg. Simple enough right?

Okay, let's work with an example. To check if the weight of a 5 month old is normal, simply add 5 to 9 which is 14 and divide by 2. You should get 7kg. So,the ideal baby's weight is 7kg.

Now, what if your 5 month old's weight is below 7kg. For instance, let's say 5kg. Well, just divide your child's actual weight with the ideal weight and multiply by 100. So, in this case 5/7 x 100 is 71.4%.

So how can one interpret that? Well, any weight above 60% and below 80% of the ideal weight is regarded as undernutrition. In the example, the child's weight is 71.4% of normal which is above 60% but below 80% so the baby is undernourished and needs to be fed more often with appropriate food to get back to the ideal weight.

If the weight calculated is below 60%, the child is malnourished and needs to be taken to a hospital for treatment. On the other hand, if your baby is so huge that the weight is 120% or above of expected, then your baby is equally malnourished and needs to see a doctor.

The normal weight is from 80% to below 120%.

So, I hope you had fun, because I know I did. Will post later the formula to determine the ideal weight of children older than a year.