Ideal weight can be a controversial subject, with widely varying opinions. The fact is there is no exact ideal weight for any one person. The body is dynamic and will change in weight from day to day regardless of how carefully you try to maintain it.
However it is certainly fair to say that there is a healthy weight range for everyone. The fact that certain weights are clearly undesirable and can lead to health problems at both the upper and lower ends of the scale indicate that there are minimum and maximum body weights that each of us would do well to stay within.
A reasonable and widely accepted scale to determine a healthy weight range is the Body Mass Index or BMI.
Body mass index is defined as the individual's body mass divided by the square of his or her height. This provides an indicator of how much an individual's body weight differs from what is normal or desirable for a person of his or her height.
However there are limitations to BMI since it does not take into consideration the true composition of a person's body i.e. how much lean mass a person has compared to fat. So for example a very fit bodybuilder might have an identical BMI to an obese couch potato based upon weight to height ratios, but this is evidently does not indicate that they are both in the same zone of healthy or unhealthy weight.
For that reason we highly recommend using some method of calculating your Body Fat % in conjunction with your weight in order to give you a better indicator of whether you are acheiving a healthy body composition.