I am fifteen and about 5/9 and i weigh around 145 possibly higher if my scale doesn't work right..am i over weight?
Your BMI might say you are, but it really depends. Muscle is heavier than fat, so even really fit athletes are considered overweight or obese on their BMI charts.
http://www.cdc.gov/healthyweight/assessing/bmi/this can help
No way, I'm 5' 9" 135 pounds, and I'm very skinny.