If you are 5'11 and weigh 150 pounds how much weight do i have to gain to be the same size as someone that is 5'8 and 130 pounds?

5'8 and 130 lbs = BMI of 19.8 5'11 and 150 lbs = BMI of 20.5 To have a BMI of 19.8, you shouldn't gain, you would have to lose about 8 lbs.