Three factors that influence an appropriate weight are height, body mass index (BMI), and body frame. A woman 5 feet tall should weigh 100 pounds, adding 5 pounds for each inch, and man 5 feet tall should weigh 106 pounds, adding 6 pounds for each inch. A BMI below 18.5 is underweight, between 18.5 and 24.9 is normal weight, and 30+ is overweight. Body frame is also an important factor when determining proper weight.