Body Mass Index (BMI)

Learn your body mass index (BMI).

How Can People Use Their BMI to Evaluate Their Bodies?

When it comes to adults and children, different methods are used to find out if weight is about right for height. Adults should learn their BMI. Not all adults who have a BMI in the range labeled "healthy" are at their most healthy weight.

  • Some may have lots of fat and little muscle.
  • A BMI above the healthy range is less healthy for most people; but it may be fine if someone has lots of muscle, a large body frame, and little fat.
  • The further one's BMI is above the healthy range, the higher one's weight-related risk. If a person's BMI is above the healthy range, he or she may benefit from weight loss, especially if there are other health risk factors.
  • BMIs slightly below the healthy range may still be healthy unless they result from illness.

BMI facts*

*BMI facts medical author:

  • BMI stands for body mass index. BMI is calculated by a formula that takes into account both a person's height and weight.
  • BMI is reported as weight in kilograms (kg) divided by height in meters squared (m2).
  • BMI is useful in classification of obesity, overweight, and healthy weight.
  • Obesity is generally defined as a BMI of 30 or greater, while healthy weight for adults refers to a BMI of at least 19 and less than 25.
  • A BMI of 40 or more is often used to identify people who are extremely obese and at risk for serious health complications of obesity.

What is BMI?

Body mass index, or BMI, is a new term to most people. However, it is the measurement of choice for many physicians and researchers studying obesity. BMI uses a mathematical formula that takes into account both a person's height and weight. BMI equals a person's weight in kilograms divided by height in meters squared (kg/m2).

What is a healthy weight?

It is important to understand what "healthy weight" means. Healthy weight is defined as a body mass index (BMI) equal to or greater than 19 and less than 25 among all people aged 20 or over. Generally, obesity is defined as a body mass index (BMI) equal to or greater than 30, which approximates 30 pounds of excess weight. Excess weight also places people at risk of developing serious health problems.

BMI chart for weight and height

The table below has already done the math and metric conversions. To use the table, find the appropriate height in the left-hand column. Move across the row to the given weight. The number at the top of the column is the BMI for that height and weight.

BMI
(kg/m2)
1920212223242526272829303540
Height (in.)Weight (lb.)
589196100105110115119124129134138143167191
599499104109114119124128133138143148173198
6097102107112118123128133138143148153179204
61100106111116122127132137143148153158185211
62104109115120126131136142147153158164191218
63107113118124130135141146152158163169197225
64110116122128134140145151157163169174204232
65114120126132138144150156162168174180210240
66118124130136142148155161167173179186216247
67121127134140146153159166172178185191223255
68125131138144151158164171177184190197230262
69128135142149155162169176182189196203236270
70132139146153160167174181188195202207243278
71136143150157165172179186193200208215250286
72140147154162169177184191199206213221258294
73144151159166174182189197204212219227265302
74148155163171179186194202210218225233272311
75152160168176184192200208216224232240279219
76156164172180189197205213221230238246287328

Body weight in pounds according to height and body mass index.

Below is a table identifying the risk of associated disease according to BMI and waist size.

BMICategoryWaist less than or equal to 40 in. (men) or 35 in. (women)Waist greater than 40 in. (men) or 35 in. (women)
18.5 or lessUnderweightN/AN/A
18.5 - 24.9NormalN/AN/A
25.0 - 29.9OverweightIncreasedHigh
30.0 - 34.9ObeseHighVery High
35.0 - 39.9ObeseVery HighVery High
40 or greaterExtremely ObeseExtremely HighExtremely High

SOURCE:

Portions of the above information has been provided with the kind permission of the Partnership for Healthy Weight Management, www.consumer.gov). Last update May 8, 2007

Medically Reviewed by a Doctor on 12/5/2016

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