Intuition and perogative.

Body mass index chart for Women, female version

A chart showing the Body Mass Index of Women, changing with age. Quite interesting, really. I bet you haven’t seen this chart anywhere else!

Calculate your own Body mass index result here.

Womens BMI chart

Betty Betty
Is my BMI average?

David David
Look on the chart, the red line at 50th percentile.

Talking Moose
Talking Moose
Or see the numbers on the bottom of this page.


Notice the "median" BMI value, which is the 50th percentile Red line. Compare it to the CDC definition of "Overweight" at BMI of 25. This is where the experts derived the famous statistic, that over 50 percent of American Women have a BMI over 25 and hence are considered overweight.

Also notice the gradual increase in Women’s body mass index over time, until age 50-60. After that, a gradual decrease in BMI occurs in older women. Each percentile line has a curved shape, even for skinny women at 25th and 10th percentiles. ( I’m hinting, without much subtlety, that a curved line is better model than a flat line across BMI=25. I’m hinting, that some weight gain during adult life is "natural".)

The chart shows how girls BMI increases with age, even beyond age 20. The children’s data came from the standard CDC growth charts. There is a gap between the children’s and adult data, because the data sources are different. The adult data (from the NHANES III survey) is more recent ( 1988-1994 ), whereas the body-mass-index-for-age charts from the CDC are based from a mix of data from old and recent sources.

This page also shows a Men’s body mass index chart (below). Comparing Women to Men, you’ll notice some differences. At less than 50th percentile, men have a higher BMI than women, which is generally thought to be due to men’s greater skeletal muscle mass. But after age 30, for the 50th percentiles or higher, overweight women rise to higher BMI levels than men. Why is that? Probably because if a woman is going to be overweight, her body accumulates fat in breasts and hips, which are places that men’s fat accumulation doesn’t occur. This female trait probably explains the higher BMI levels in overweight women.

Mens BMI chart


I realize the charts can be hard to read, so the table below shows actual numbers:

The “National Average” Median Body Mass Index values for Women are:
Age: 20-29 yrs 30-39 yrs 40-49 yrs 50-59 yrs 60-69 yrs
Median BMI:







Surf onward to:

January 29,2015 update. If you are over age 50, you REALLY ought to see this page, proving that having a BMI of 25 to 30 is actually healthiest, and not overweight.

Below are a bunch of random Q&A on body mass index…

  • How is BMI used? BMI is used as a screening tool to identify possible weight problems for adults. However, body mass index is not a diagnostic tool. To determine if excess weight is a health risk, a healthcare provider would need to perform further assessments. These assements may include skinfold thickness measurements, evaluations of diet, physical activity, family history and other appropriate health screenings.
  • Why use BMI to measure overweight and obesity? Calculating BMI is one of the best methods for population assessment of overweight and obesity. Because the calculation requires only height and weight, it is not costly and it’s simple to use for clinicians and for the general public. The use of BMI allows individuals to compare their own weight status to that of the general population.
  • What are some other ways to measure obesity? Other ways to measure obesity are skinfold thickness measurements, calipers, underwater weighing, bioelectrical impedance, dual-energy x ray absorptiometry (DXA), and isotope dilution. However these methods are not always readily available, they are either expensive or need highly trained personnel.
  • How reliable is BMI as an indicator of body fatness? The correlation between the BMI number and body fatness is fairly strong. However it varies by gender, race, and age. These variations include: At the same BMI, women tend to have more body fat than men. At the same Bmi, older people, on average, tend to have more body fat than younger adults. And highly trained athletes tend to have a high BMI because of increased muscularity rather than increased body fatness.
  • What is considered a healthy BMI? Between 20 and 25.
  • What does your BMI mean? BMI under 18.5 – is considered very underweight and possibly malnourished, 18.5-24.9 – you have a healthy weight range for young and middle-aged adults, 25.0 to 29.9 – you are overweight and over 30, you are considerd obese.
  • What are some exceptions to the rule? BMI does not differentiate between body fat and muscle mass. This means there are some exceptions to the BMI guidelines.
  • What are the health consequences of overweight and obesity for adults? Hypertension, dyslipidemia, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea and respiratory problems, and some cancers including endometrial, breast, and colon.
  • Is BMI interpreted the same way for children and teens as it is for adults? Yes, but however, the criteria used to interpret the meaning of the BMI number for children and teens are different from those used for adults. For children and teens, BMI age, and gender-specific percentiles are used for two basic reasons: 1) the amount of body fat changes with age, and 2) the amount of body fat differs between boys and girls.

Did you click on any faces or find other surprises?


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