You might aspire to have chiseled abs or perfect glutes, but staying fit and maintaining a healthy weight will benefit your health, too. Being overweight can increase your risk of chronic diseases, including some types of cancer, while being underweight can affect your hormone balance and immune function. While there's no single "perfect" weight, you can get a rough idea of a healthy weight range based on your height.
Body Mass Index is Based on Weight and Height
One of most widely recognized methods of assessing weight status in relation to height is the body mass index, or BMI. You can calculate your BMI with the following formula:
BMI = weight in pounds / (height in inches x height in inches) x 703
For example, if you are 5 feet 5 inches tall and you weight 135 pounds, your BMI would be 22.5, or in the healthy range. According to the Centers for Disease Control and Prevention, a BMI between 18.5 and 24.9 indicates a healthy weight for an adult age 20 or older. A BMI below 18.5 is underweight, a BMI between 25 and 29.9 is overweight, and a BMI of 30 or more indicates obesity.
BMI can vary depending on bone structure, frame size and muscle mass. You should aim to fall somewhere in the range of 18.5 to 24.9 for a healthy body weight, however. If you are 5 feet 5 inches tall, that would be between 111 and 150 pounds.
Healthy Body Weight Isn't Based on Age
Age is not a factor in the formula used to calculate BMI. But age does have an effect on ideal body weight. For children and teens under the age of 20, BMI is compared to age on a growth chart developed by the Centers for Disease Control and Prevention. Your pediatrician can help you determine a healthy weight for a child or teenager.
While the BMI measure is for all adults ages 20 and older, there's some evidence that a BMI of 18.5 to 24.9 is not a healthy goal for older adults. BMI doesn't distinguish between fat and muscle mass, even though your body fat levels impact your health. And because you tend to lose muscle and bone -- and gain fat -- as you age, BMI is less accurate in older adults. If you're concerned about your weight, consult your doctor for a personalized assessment.
Use Body Fat Percentage to Set Goals
While BMI is a useful tool to estimate how much you should weigh, BMI does not tell the whole story. It might not work if you're very athletic -- that extra muscle mass might bump you into the "overweight" or "obese" category, even if you're at a low body fat level. Your BMI can give you a good starting goal for your ideal body weight, but if you are looking for a more precise goal, contact a physician or fitness trainer to measure your body fat percentage using professional testing methods, like skinfold measurements or body scans.
Body Shape Matters
While a healthy body weight is important for your health, the number on the scale is not the only factor you should consider. According to the University of Pittsburgh, the shape of your body says a lot about your health. A pear-shaped body, which stores excess fat in the hips and thighs, is at a lower risk of chronic disease than an apple-shaped body, which stores fat around the abdomen. Doctors measure waist circumference to help assess the fat stores around the abdominal organs and predict risk for disease. In addition to maintaining a healthy body weight, aim for a waist circumference lower than 35 inches for women and 40 inches for men.
- Centers for Disease Control and Prevention: About Adult BMI
- American Council on Exercise: Helpful Formulas
- American Council on Exercise: What Is Body Mass Index and Can I Rely On It?
- The New England Journal of Medicine: The Effect of Age on the Association Between Body Mass Index and Mortality
- American Journal of Epidemiology: Obesity and Mortality Risk: New Findings From Body Mass Index Trajectories
- Journal of the American Geriatrics Society: Body Mass Index and Survival in Men and Women Ages 70 to 75
- University of Washington: Desirable Weight Tables
- University of Pittsburgh Medical Center: What Your Body Shape Says About Your Health
- Today's Dietitian: Underweight: A Heavy Concern
- Nutrition411: Use of BMI in Older Adults