How can I check how much of my weight is muscle and how much is fat? I see a lot of people setting goals on what % they want to get but I'm not sure where I'm starting at to set new lower goals. I have seen ones online that ask your hieght age and weight, but didn't know how acurate they are. Are they trust worthy? If not what is the best way to find out how much of me is fat.

There are a variety of devices for measuring bodyfat, some more accurate than others. The most popular, I believe, are the skin calipers. Fairly cheap, and fairly accurate. The BF scales aren't all that accurate, and BMI calculations are about worthless. One way is to just post a pic and get some estimates.

At your age, I would really question if setting your sights on a specific BF% is an important or particularly healthy goal to have. I say this in regards to worrying about whether you are something like 14% or 10%. You definitely want to be within a healthy range, but you probably don't need any advanced methods to determine whether fat loss needs to be made a priorty for you. Just looking in the mirror should be enough of a clue.

Goals such as increasing athleticism, strength, speed, endurance, power output, etc are better in the long run. If you focus on these qualities, the BF% will definitely take care of itself as the body doesn't perform at its best when the ratio of lean mass to fat becomes distorted.

What are your current body stats in regards to height, weight, and waist size?

You can read over the body fat percentage info at wikipedia for more info on various methods of assessment. The DXA scan method is the cool stuff. :)

If you contact a professor in your local university's Health & Human Performance department (or whatever they call it there) you can find someone who will hydrostatically weigh you. Ask around.

I'm getting weighed this Saturday at my local university.

Probably cost you $30 or so.

Goonie's advice is wise though. You're probably wasting your energy worrying about body fat at fifteen years old. Just eat right and lift.

Thanks for all the advice. And for goonie I'm about 5'4 130pounds with a 30 inch waist.