How Are Overweight and Obesity Diagnosed?

The most common way to find out whether you're overweight or obese is to figure out your body mass index (BMI). BMI is an estimate of body fat, and it's a good gauge of your risk for diseases that occur with more body fat.

BMI is calculated from your height and weight.

You can use the chart below or click here for the National Heart, Lung, and Blood Institute's (NHLBI's) online BMI calculator to figure out your BMI. Or, your health care provider can measure your BMI. You can also download the BMI calculator app for iPhone app (link is external) and Android app (link is external).

Body Mass Index for Adults

Use this table to learn your BMI.

First, find your height on the far left column.

Next, move across the row to find your weight. Weight is measured with underwear but no shoes.

Once you've found your weight, move to the very top of that column.

This number is your BMI.

Height	21	22	23	24	25	26	27	28	29	30	31
4'10"	100	105	110	115	119	124	129	134	138	143	148
5'0"	107	112	118	123	128	133	138	143	148	153	158
5'1"	111	116	122	127	132	137	143	148	153	158	164
5'3"	118	124	130	135	141	146	152	158	163	169	175
5'5"	126	132	138	144	150	156	162	168	174	180	186
5'7"	134	140	146	153	159	166	172	178	185	191	198
5'9"	142	149	155	162	169	176	182	189	196	203	209
5'11"	150	157	165	172	179	186	193	200	208	215	222
6'1"	159	166	174	182	189	197	204	212	219	227	235
6'3"	168	176	184	192	200	208	216	224	232	240	248

This table offers a sample of BMI measurements.
If you don't see your height and / or weight listed on this table, go the NHLBI's complete BodyMass Index Table

What Does Body Mass Index Mean?

BMI
18.5–24.9	Normal weight
25.0–29.9	Overweight
30.0–39.9	Obese
40.0 and above	Extreme obesity

Although BMI can be used for most men and women, it does have some limits. It may overestimate body fat in athletes and others who have a muscular build.

BMI also may underestimate body fat in older people and others who have lost muscle.

Body Mass Index for Children and Teens

Overweight and obesity are defined differently for children and teens than for adults. Children are still growing, and boys and girls mature at different rates.

BMIs for children and teens compare their heights and weights against growth charts that take age and sex into account. This is called BMI-for-age percentile.

A child or teen's BMI-for-age percentile shows how his or her BMI compares with other boys and girls of the same age.

For more information about BMI-for-age and growth charts for children, go to the Centers for Disease Control and Prevention's BMI-for-age calculator.

What Does the BMI-for-Age Percentile Mean?

BMI-for-Age Percentile
Less than 5th percentile	Underweight
5th percentile to less than the 85th percentile	Healthy weight
85th percentile to less than the 95th percentile	Risk of overweight
95th percentile or greater	Overweight

Waist Circumference

Health care professionals also may take your waist measurement. This helps screen for the possible health risks related to overweight and obesity in adults.

If you have abdominal obesity and most of your fat is around your waist rather than at your hips, you're at increased risk for coronary heart disease and type 2 diabetes. The risk goes up with a waist size that's greater than 35 inches for women or greater than 40 inches for men.

You also can measure your waist size. To do so correctly, stand and place a tape measure around your middle, just above your hipbones. Measure your waist just after you breathe out.

Specialists Involved

A primary care doctor (or pediatrician for children and teens) will assess your BMI, waist measurement, and overall health risk.

If you're overweight or obese, or if you have a large waist size, your doctor should explain the health risks and find out whether you're interested and willing to lose weight.

If you are, you and your doctor can work together to create a treatment plan. The plan may include weight-loss goals and treatment options that are realistic for you.

Your doctor may send you to other health care specialists if you need expert care.

These specialists may include:

An endocrinologist if you need to be treated for type 2 diabetes or a hormone problem, such as an underactive thyroid.

A registered dietitian or nutritionist to work with you on ways to change your eating habits.

An exercise physiologist or trainer to figure out your level of fitness and show you how to do physical activities suitable for you.

A bariatric surgeon if weight-loss surgery is an option for you.

A psychiatrist, psychologist, or clinical social worker to help treat depression or stress.

This video—presented by the National Heart, Lung, and Blood Institute, part of the National Institutes of Health—shows that even a few extra pounds can affect your health and life more than you may think. Average people in a park—not actors—are asked to carry a 10-pound sandbag, and report how the added weight affects them and their ability to carry out normal, everyday activities.

Click here for the Video