How much should i weigh if i'm 5 foot 3 and 18 years old and a female?

115.5: This is an ideal body weight for your height.

Range of normal: Based on bmi the range of normal weights at 18 is from 109 to 134 which includes 50% of young women at that height. Using cdc growth charts the same range is seen with a mean or average of 116 lb. You can download a chart from the cdc websight and compare different values for yourself. See ; www.Cdc.Gov/growthcharts.