BMI is a 2 dimensional equation. I does not take into account how much of the body weight is muscle, fat, and other materials. therefore it is very common for a body builder to be classed as obese according to their BMI result. we live in a 3 dimensions, BMI is not a good tool.
Right, a year and a half ago I wrote a answer for the distribution of weight, explain the distribution of the fat, muscle and the rest of weight(Organs, blood, bones, etc), and how the calories afect the weight in relation with height, weight, activity and other paraments, you can check hear in this link:
I think that I am someone with a kink for the numbers for this. You can see this tool how a little help.
As an actual health tool? No, BMI is not that useful. You are correct. But it does do something useful for me. It mathmatizes the relationship between height and weight.
I can say “Ok, I am this tall, and I weigh that much” and that gives me a single, concrete number that I can mentally associate with the way someone looks in my brain. So if I then want to change one of the ways someone looks, say, height. I don’t then have to completely re-imagine what that looks like. I can just look at the resulting BMI, and have a pretty decent approximation, assuming that the person in question is mostly blubber. (and. I mean, where are you?? what is the name of this website. It works for us if we want it to)