Use the form below to easily and quickly calculate your Body Mass Index (BMI).
BMI is a simple method to assess weight in relation to height. However, it is important to note that it does not provide information about body composition or the distribution of body components.
For example:
Additionally, caution is needed when using it for elderly individuals, as BMI values may vary without necessarily indicating health issues, unlike in younger adults.
Enter your details in the form to calculate your BMI and get an initial assessment of your weight status!
What else can I do besides BMI to determine if my weight is healthy?
First, you can measure your waist circumference!
Waist circumference (WC), combined with BMI, provides a useful indicator that is directly linked to the health risks associated with obesity. When WC exceeds 102 cm for men and 88 cm for women, there is a significantly increased risk of health complications, such as the development of diabetes, cardiovascular problems, and high blood pressure. Therefore, we could say that a very high BMI combined with an off-limit WC value serves as a strong "warning" to improve your body. However, if your measurements are below these values, there's no need to worry about obesity and its associated risks.
Body fat measurement is a process that will assess and evaluate your body's composition, including the fat mass and lean mass (muscle mass, fluids, bones). Based on today's available technology, there is also the possibility to assess the distribution of fat in your body, meaning how much fat you have on your torso, arms, and legs. This way, you'll have an overall picture of your body and be able to understand what changes are needed.
In which categories of people is BMI not used and why?
They often appear to be classified as overweight (For more information, see the question “What is the flaw of BMI?”).
It is obvious that BMI cannot be applied to women during pregnancy, as it does not take into account the baby and the additional weight that needs to be gained for its proper development.
BMI is intended solely for adults. For these age groups, growth curves are used, based on the child's gender and age.
This group has lost some amount of muscle and bone mass. Therefore, their BMI might fall within a normal range, while in reality, they may be overweight.
It is important to mention that BMI calculation is mainly based on the body types of Caucasians and may not be suitable for people of other ethnicities. Specifically, compared to white Europeans with the same BMI, Asians tend to have 4% higher total body fat, while South Asians have particularly high levels of abdominal obesity, which can also affect the BMI measurement.
How was someone's body assessed before the use of BMI?
BMI became an international standard for measuring obesity in the 1980s, and the general public learned about it in the 1990s when the U.S. government launched an initiative to promote healthy eating and exercise.
Before 1980, doctors used weight-for-height charts (different for men and women) that described body weight for each centimeter of a person's height. These charts were limited because they only used body weight and not body composition. In 1998, the National Institutes of Health lowered the overweight threshold for BMI from 27.8 to 25 kg/m² to align with international guidelines.
This move alone added about 30 million American citizens, who were previously considered to have a "healthy body weight," to the "overweight" category. Since then, BMI has been used as we know it today.
When should BMI make me worry about my health?
Any BMI value outside the normal range should be a cause for concern. The most concerning category for you is obesity, which is known to pose the most significant and serious health risks, some of which include:
It is also worrying if your BMI places you in the underweight category, as there are numerous risks associated with this, such as:
Although this category also carries risks, you may be less concerned if you're overweight, because losing a few kilograms can bring you to a normal weight. However, be cautious, as gaining just a few kilograms may push you into the obesity category. In general, it is important to know that the closer you are to a normal BMI, the less you need to worry. This does not mean you should be complacent, as BMI merely places you in a category without guaranteeing your health, even if you are in the most desirable range. However, the further you are from the desired values, the greater the potential consequences. Therefore, if you're far from the range of 18.5–24.9 kg/m², don't waste time and start working towards it today.
How many kilograms am I away from a "normal" body weight?
Let's go through together how to find the number of kilograms you are "away" from a normal body weight in 4 simple steps, with an example.
Step 1: Find a calculator. If you don't have one handy, use an online one:
Step 2: Enter your height and multiply it by itself (or square it).
Example: For a height of 1.80 m and 92 kg, we do:1.80 * 1.80 = 3.24 m²
Step 3: Multiply the number you obtained by 18.5 kg/m² if you're underweight, or by 24.9 kg/m² if you're overweight or obese.
Example: Since you are overweight with these kilograms,3.24 * 24.9 = 80.7 kg
Step 4: If you are underweight, subtract your weight from this number. If you are overweight or obese, subtract this number from your weight.
That's it! The number of kilograms you are away from a normal body weight according to BMI will appear on your screen.
Example: 92 - 80.7 = 11.3 kg.So, for this example, you would need to lose 11.3 kg to be in the normal BMI range for this height and weight.
These kilograms place you on the borderline of the normal BMI range. Ideally, we would want you to lose or gain a little more so that you don’t risk moving into another category. However, it’s important that this is done under the guidance of a specialist. In this direction, the methodology I apply in my practice includes both the regulation of your energy balance and your nutritional education.
What is the flaw of BMI?
A key flaw of BMI is that it does not differentiate between body fat and muscle mass. To better understand what this means, here’s an example:
Imagine a sedentary person who is 1.80 m tall and weighs 92 kg. They would have a BMI of 27 kg/m², which automatically classifies them as overweight. Using the same logic, the famous basketball player LeBron James weighs 113 kg and is 2.06 m tall. He has a BMI of 26.63 kg/m² and is also categorized as overweight. Comparing their BMIs, you would think they have similar body compositions.
However, you would be completely wrong. This is because LeBron James’ body is primarily composed of muscle mass, which weighs more than fat in the same amount. Therefore, an extremely fit person can have a similar BMI to someone who may not have exercised for years, reducing their muscle mass and increasing fat. And this is because BMI does not distinguish between body fat and muscle mass!
What is the history of BMI?
It’s interesting that BMI was not discovered recently. In the 1840s, a Belgian statistician named Adolphe Quetelet devised an index that he called the "Quetelet Index of Obesity," a simple mathematical formula to calculate obesity. Specifically, it involved dividing a person’s weight (in pounds or kilograms) by the square of their height (in centimeters or inches).
The formula was: Weight / height²
Quetelet wrote:
"If a person grows equally in all dimensions, their weight at different ages would be the cube of their height."
He continued explaining that during the first year of life, our width is indeed greater in proportion to our height, but after that, we grow more in relation to our height. It’s important to note that when Quetelet developed this index, he had no interest in studying obesity. In fact, Quetelet was more interested in developing a relative weight index.
After World War II, given reports of increased mortality and morbidity among overweight and obese individuals, the validity of the Quetelet index was confirmed, and it became widely used as a useful index of general relative body weight. It was later renamed the Body Mass Index (BMI) and was adopted by the World Health Organization in 1995 as a simple tool to quickly and easily estimate obesity levels in a population.
Can I draw conclusions about my body fat from my BMI?
No! BMI does not reveal your body composition; it simply categorizes you based on your weight and height. If you're interested in your body fat, muscle, or skeletal mass, we can schedule a body composition analysis session at the office.
Does BMI alone cover everything for me?
No! While BMI is the most widely used indicator for evaluating your body weight, it is just a sign.
There are many other things you can do and learn to understand exactly the condition your body is in. Additionally, there are cases where it does not apply or even situations like increased water retention where it may be misleading. However, it is still a very important indicator because with a few simple details, it provides an initial assessment.
Indicative Bibliography
Tine RCK, Faye B, Ndour CT, Sylla K, Sow D, Ndiaye M, Ndiaye JL, Magnussen P, Alifrangis M, Bygbjerg IC and Gaye O. Parasitic Infections among Children under Five Years in Senegal: Prevalence and Effect on Anemia and Nutritional Status. ISRN Parasitology, 2013; 2013: Article ID 272701, 6 pages
Bates GW, Bates SR, Whitworth NS. Reproductive failure in women who practice weight control. Fertility and Sterility1982; 37(3): 373-378
Mata LJ, Kromal RA, Urrutia J J & Garcia B. Effect of infection on food intake and the nutritional state: perspectives as viewed from the village. Am. J Clin. Nutr. August 1977; 30 (no. 8): 1215-1227
Klatsky, A., 2017. Body Mass Index and Mortality in a Very Large Cohort: Is It Really Healthier to Be Overweight?. The Permanente Journal,.
Dalvand, S., Koohpayehzadeh, J., Karimlou, M., Asgari, F., Rafei, A., Seifi, B., Niksima, S. and Bakhshi, E., 2015. Assessing Factors Related to Waist Circumference and Obesity: Application of a Latent Variable Model. Journal of Environmental and Public Health, 2015, pp.1-9.
Nhlbi.nih.gov. n.d. Assessing Your Weight and Health Risk. [online] Available at: <https://www.nhlbi.nih.gov/health/educational/lose_wt/risk.htm
Ross, R., Neeland, I., Yamashita, S., Shai, I., Seidell, J., Magni, P., Santos, R., Arsenault, B., Cuevas, A., Hu, F., Griffin, B., Zambon, A., Barter, P., Fruchart, J., Eckel, R., Matsuzawa, Y. and Després, J., 2020. Waist circumference as a vital sign in clinical practice: a Consensus Statement from the IAS and ICCR Working Group on Visceral Obesity. Nature Reviews Endocrinology, 16(3), pp.177-189.
Heymsfield, S., Peterson, C., Thomas, D., Heo, M. and Schuna, J., 2015. Why are there race/ethnic differences in adult body mass index-adiposity relationships? A quantitative critical review. Obesity Reviews, 17(3), pp.262-275.
Gutin, I., 2017. In BMI we trust: reframing the body mass index as a measure of health. Social Theory & Health, 16(3), pp.256-271.
Centers for Disease Control and Prevention. n.d. About Child and Teen BMI. [online] Available at: <https://www.cdc.gov/healthyweight/assessing/bmi/childrens_bmi/about_childrens_bmi.html>
Robert H. Shmerling, M., 2016. How useful is the body mass index (BMI)? – Harvard Health Blog. [online] Harvard Health Blog. Available at: https://www.health.harvard.edu/blog/how-useful-is-the-body-mass-index-bmi-201603309339
Eknoyan, G., 2007. Adolphe Quetelet (1796 1874) the average man and indices of obesity. Nephrology Dialysis Transplantation, 23(1), pp.47-51.
