Calorie needs wrong?

So, using the kids' BMI calculator, I found that I need about 1500 calories sedentary and 1750 calories with light activity (I'm pretty small/short - 5'1" :)). However, I eat more than that, usually between 2000 and 2500 calories with no exercise except the occasional walking from one place to another. Aside from the usual fluctuations, I'm maintaining my weight on more than I "should." 

Does this mean that the BMI calculator is not always right? I'm not going to follow it or anything, but I was curious how a calculator could possibly know how much each person needs. 

The calculators aren't always right. If you have big bones, or lots of muscle, it might say you are overweight when your not.

The calculators are just a guideline for the "average" person.

The calculators will give you a ballpark estimate which you can adjust up or down from.  The actual numbers depend on you and your routines specificially.

Perhaps your walking is sufficient to bump you up an exercise category?

Well, I usually walk about an hour a day (getting around campus, etc). I also run cross country and track and I obviously eat closer to 2500 calories a day on practice days. Do you think that even on days I don't do exercise, the exercise I do on other days speeds up my metabolism in general?

Thanks for the replies!

I think there's some carryover, perhaps not quite as much as I'd like, but some.  If you're under 21 though you get a much higher return on your exercise than CC tends to estimate.  Do you have a heart rate monitor so you can check on that?

no, i don't have a heart rate monitor, but it's not that big of a deal. i was just curious. people always talk about how some people just have a high metabolism and are able to stay thin, but i don't really know how metabolism works. it seems strange how there's a number for how much your body needs.

http://www.webmd.com/fitness-exercise/guide/m ake-most-your-metabolism

An interesting article on metabolism.  I don't know how accurate it truly is but it sounds reasonable.

at 15 years old and 115 pounds--estimate since you didn't specify---and less than 1 hour of activity this calculator comes up with almost 2000 calories, with your light activity, you probably fall between the less than 1 hour and 1 hour a day activity level which would put you between the 1982 and 2277, which is 2129 averaged...which falls within your range...so this would make sense. i don't know your exact stats but all of the calculators are different and will suggest different amount based on the goal of the calculator...if there is an assumption of weight loss as a goal it might decrease the recommendation. anyway, here is the calculator. play with it...maybe it is more accurate than the one you were using :) 

http://www.bcm.edu/cnrc/energy_calculator.htm

(edit: sorry, wrong thread)

hmm, interesting.

chrissy - i'm actually 19, but i know (and hope) that i'm still growing, so i consider myself to be a child :) i plugged my stats into the calculator and i think it's interesting how there's such a discrepancy between calorie needs for less than an hour of activity versus an hour of activity.

i guess it makes sense that i'm eating what i'm eating then. it's just difficult to gauge what is "sedentary" and what is "light", "moderate", or "high" activity.

with no exercise it says i need 1900, i eat 3000 plus without exercise and maintain, so in a way it can be wrong, everyone is different.