Setting goals, measuring your progress and making ongoing adjustments to your behavior is one of the best techniques to accomplish almost anything you set out to do. This is holds no less true when it comes to losing weight. Using body weight charts to set and measure progress toward weight goals is a smart way to manage your weight.
One of the most widely-acknowledged types of body weight charts is the Body Mass Index, or BMI. Medical doctors and nutritionists the world over use the BMI method for helping to determine whether people are at a healthy weight. You can use the Body Mass Index whether you use the metric system or pounds and inches.
Here is a step-by-step method for calculating your BMI, along with tips for what to do if your number indicates that you are overweight.
1. Weigh yourself
Start by weighing yourself. Any household scale will do. Record your weight in either pounds or kilograms*.
2. Measure your height and square it
Next, use a simple household measuring tape and measure your height. Note: if you measured your weight in pounds, measure your height in inches.
* If you measured your weight in kilograms for #1 above, measure your height in centimeters and then convert to meters (e.g., 165 cm = 1.65 meters). Now, square your height (i.e., multiple the number times itself).
3. Divide your weight by the square of your height
Now, it is just “weight divided by square of your height” (or, #1 / #2, above). Okay, you are almost there!
4. Finally, multiply by 703 (if not using the metric system)
In fact, if you were using the metric system (kilograms and meters) above, you are done: this is your BMI! If you were using pounds and inches above: multiply your answer in #3 by 703. This is your BMI.
5. Determine what your BMI means
Okay, now you have a BMI number. But, what do you do with it? Okay, here is what your number means in terms of whether you are likely at a healthy weight:
under 18: you are underweight
18 to 18.5: you are thin
18.6 to 24.9: you are at a healthy weight
25 to 29.9: you are overweight
over 30: you are obese
6. Limitations of BMI as an indicator of health
If you are not happy with your BMI number and what it means about the health of your weight, first, don’t panic just yet: this system is not perfect! For example, it does not take into account your muscle mass or body type. So, if you are particularly muscular, for example, you may have a BMI that is well over 25 but you could still be considered to be at a healthy weight.
7. What to do if you are overweight
If your BMI indicates that you are overweight, you need to decide if you are willing to commit to getting yourself down to a healthy weight. That will likely mean a combination of exercise and eating right. Take the time to educate yourself now as to how to best get your body weight into a healthy range.
The BMI is just one indicator of healthy weight. Other valid indicators used by doctors and nutritionists today include skinfold thickness measurements (using calipers), underwater weighing, and bioelectrical impedance testing. However, BMI is by far the simplest method for measuring your health in terms of weight.