How much should a 10 year old boy weigh?
For a ten year old boy, I think they should weigh 75 to 80
It depends more on their height than their age. Their body mass
index (BMI) can be a reasonable measure of whether they are at a
suitable weight. It can be calculated by dividing their weight in
kilogrammes by their height in metres squared, and comparing the
answer to values given on a chart. (There are charts available for
free from many websites with a quick search, E.g. one is available
on the wikipedia page for BMI
So if for example the 10 year old was 1.2 metres tall and
weighed 40 kilogrammes, their BMI would be:
1.2 x 1.2 = 1.44
40 ÷ 1.44 = 27.78 (Overweight according to the chart)
Bear in mind that the chart isn't always completely reliable,
for example a very muscular person may be classified as overweight
due to the weight for their height.