Calculate your target weight based on your height and desired BMI. BMI stands for Body Mass Index. When you enter your current weight, the system will also calculate how much you need to gain or lose to reach your goal, and then calculate and display your current BMI. A specific BMI is required for some professions, and you may also want to pursue a BMI as a health goal. This calculator is helpful in such cases, among others.
For example, if you are 180 centimeters tall and have a weight of 95 kilograms, your BMI is 29.3. If you want to reach a BMI of 25, you need to lose 14 kilograms.
The BMI to aim for of course varies individually. A BMI within the normal range is often desirable; for this, see the table in the BMI calculator. However, the BMI only takes into account the weight of the body, physically accurate this is the mass, and not what that mass consists of. Therefore, this value doesn't determine whether a high BMI means a lot of muscle or a lot of fat, which obviously makes a big difference. With higher muscle mass, a higher BMI is less likely to indicate obesity and the associated health risks. For other metrics that take this into account, see ABSI and the waist to hip ratio. Incidentally, muscles are heavier than fat for the same volume, meaning they have a higher density.
If a BMI target is given by sports physicians or nutritionists, or as a professional requirement, then this value was probably determined in conjunction with other factors that also take the type of body mass into account. In general, it is sensible not to view BMI as the only value, but rather as a parameter that has only limited significance on its own and should be interpreted together with other values by appropriate experts.