just type in your height and your weight.
it lists what your BMI (body mass index) is and it lets you know the cut offs for when you're underweight, normal weight, overweight and obese.
For example. a gal who is 5' 4", the LOWEST weight she may be and still remain at the very bottom of the normal weight is 107.5 lbs. At 107 she becomes overweight. At the other end of the scale, she may still weigh 144.8 lbs and still be in the normal weight range/category. However, at 144.9 she'd slip into the overweight range.
So you may see, the NORMAL range is OVER 37 lbs for a gal who is 5' 4". THAT allows for those who are big boned vs. those who aren't. 37 plus pounds is quite a range just for the normal range.