Originally Posted by ivegotabike
im 6' 1" 146 pounds, BMI=19.3 it says im underweight
Who said you were "underweight"? According to the National Institutes of Health, and the World Health Organization, "underweight" is 18.5 and below.
FWIW, here's a good online calculator for those who don't want to pull out the calculator...it also includes some interesting statistics on how your BMI compares to others of your age, height, and gender:
http://halls.md/body-mass-index/bmi.htm