I'm 17, a female, and i weigh 154, what is my bmi? what should my bmi be at 17? what all do i need to do to achieve my appropriate bmi?

Need your height: Hi. To calculate your BMI, we need your height and weight. We can't get BMI from just your weight. If you want to give your height and weight, we'll give you your BMI (or you can go online and use a BMI calculator). Eat healthily, exercise regularly for life, and don't smoke. Good luck!

BMI: To be able to get precise measurement, we need to know how tall you are. Thanks.

Need height.: The BMI is a measure of your weight with respect to your height, so I'd need to know your height. You can calculate it yourself at the following website: http://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm. As you can see, BMI is a range, not one single number. Falling anywhere in the "normal" range, not under, would be just fine.