Since the late 1800’s, body mass index (BMI) has been one of the widely used methods to check whether an individual is at a health weight for his or her height.
This health metric correlates the total weight of an individual against his or her height, with possible results graded as underweight, normal, overweight, or obese.
As obesity rates have exploded over the past two decades, BMI has become an important data point to determine an individual’s overall health.
Fine Tuning BMI Calculations
In fact, if you’ve had a physical check-up with your doctor at any point in your adult life, it’s very likely your BMI was measured and added to your medical records.
But did you know you that the way your BMI results are used can differ depending on your gender?
That’s right, doctors have begun moving away from the “one size fits all” approach used for so long in favor of a more fine tuned calculation based on gender.
According to scientific research, an average woman has about 25% body fat by weight while an average man has just 15% body fat by weight.
Men are generally more muscular, while women have more fat deposited on the body especially around their glutes, hips and thighs.
How is BMI Calculated for Females?
Since the BMI correlates body weight and body height, the same components of the general BMI calculation are used.
BMI = mass (lb) / (height ((inches))2 x 703
Fortunately there are many free online resources that prompt you to enter your height and weight and calculate your BMI automatically.
Once you know your BMI, you can see what specific weight segment you fall under:
- Very Severely Underweight: <15
- Severely Underweight: 15.0 to 16.0
- Underweight: <18.5
- Normal: 18.5 to 24.9
- Overweight: 25.0 to 29.9
- Moderately Obese: 30 to 35
- Severely Obese: 35 to 40
- Very Severely Obese: >40
Keep in mind that a BMI reading doesn’t equate to an equal body fat composition between men and women.
A female BMI needs to be adjusted to create a more accurate impression of fat deposits on her body. Additional lifestyle variables such as age and level of physical activity can be factored into the calculations to more accurately assess if an individual is at a healthy weight.
Going Beyond BMI Index for Females
Although BMI gives a good snapshot on how healthy one’s weight is, it’s worth noting that this is just a screening test and there are plenty of other tests that can, and should, be taken if an you fall in an unhealthy BMI range.
Excessive accumulation of fat around the waist, abdomen, and arms is considered a significant indicator of unhealthy fat. This type of fat, also known as white adipose tissue, may have a negative impact on one’s health.
On the other hand, extensive fat deposits on the hips, thighs and glutes but not the arms, waist, and abdominal region is considered healthy.
Summary
BMI is an important health metric that can provide a snapshot of an individuals overall health.
The same method is used to calculate BMI for both genders. Because women generally have less lean muscle mass than men, they should always use BMI calculators designed for females when determining BMI.
I recently had a checkup and I knew that my BMI was measured, but wasn’t sure on what the method was to calculate it. Thanks for the description and the graphic. It really helped me to understand more clearly.
I have an issue with the whole BMI thing. It goes based off of height and weight but it doe not take into account that women have different frames as well. According to this I am nearly “obese” and that is just ridiculous. My waist isn’t even 30 inches! I go based on the waist should be half or less than half of your height. Since I am 5’3, my waist should be no larger than 31.5 and that to me is more accurate than this.
I agree. Ihave always thought bmi calculators were not the best way to calculate these things. I follow one girl on tumblr who posts photos of herself, and she claims her BMI says she is obese. However, her body could fit into the high normal range.
I have a similar story as well right now. When I was younger I was very fit and into strength training. I’m starting to get back into it and am now the size I was before I marries my now ex husband. I can’t fit into my old clothes though so I ended up doing a body fat analysis. The last time I was at my current weight I was about 18% and now I’m 27%, which is considered high or overweight for a woman. According to bmi charts, though, I’m in the healthy range.
I’ve heard of BMI before, but I never actually considered it as health metric. It’s easy enough to compute, but I kinda don’t want to know if I’m obese, haha. In any case, I might humor myself and try to get my BMI. Now if only I could find that weighing scale.
Thank you for this article. The company I work for recently had a yearly medical check-up. Since there were so many of us, the doctors were not able to thoroughly explain the medical results due to time constraints. They just handed us a pice of paper with the results. For BMI, they just put a number. They did not specify what the number indicates. I am glad to learn that I am in the Normal range.
One thing that I never understood about calculating BMI is that it never seems to take into account that muscle weighs more than fat. So technically if a body builder (male or female) weighed themselves, then took their height and did the calculations, wouldn’t they be considered obese because they would end up with a higher BMI? But they aren’t obese, they just have a lot of muscle. That’s what I never understood about the formula they give to calculate BMI, to me it seems more accurate when the actual amount of body fat is measured, though you can’t exactly do that at home.
This was my thought exactly, most BMI measurements take the fat test pinch and measure inches like that, what if you just had saggy skin or real elastic skin? What if you just had a baby?
I don’t think that the old way of measuring BMI is right for today. People are bigger then our grandparents were in their time.
I think this is an important issue as health is closely tied to your job in some cases, and in insurance premiums in all cases. The water offset for BMI maybe the best indicator of true fat to date.
Thank you for sharing this article. I have always been a bit skeptical about the methods used to measure BMI. I worked in the fitness field in my early to mid 20’s back in 1996 and it was even a questionable way to measure one’s health back during that time, due to muscle weighing more than fat. This method of calculation was especially bothersome to bodybuilders who carried more muscle mass and tested out on the higher end of the BMI charts. So, hopefully Science will push forward to find ways to make this a more reliable form of measurement, especially since some insurance companies are using the BMI measurement of members to determine premium rates as they are doing for the company I am working for.
This was a very interesting read. It’s good to know the differences between men and women with regards to their bodies. I also agree with a point someone made earlier about how everyone has different body frames, so that may be something else to consider when determining one’s BMI.
I don’t remember the last time I had my BMI calculated, though I would assume I’m nearing the “obese” end of the scale. Fortunately, I’ve been trying to work out more and more everyday, so hopefully that’ll change soon.
And the next time I see my doctor and she calculates my BMI, I’ll be sure to ask how it was calculated.
I never knew how BMI was calculated by my doctor. I always knew that there was a difference between how the calculation was for women and men but I didn’t realize that women had more body fat than men. Thanks for the insight, now if I could just get my BMI lower I’d be very pleased.
I like the idea of using BMI as a screening test and not reading too much into the number before other tests are taken. There are so many factors that contribute to our body composition. It is best to talk to a professional about your health and take additional, more conclusive, tests if necessary. However, a BMI number above or below normal is definitely reason to speak to someone about your health, so it serves an important purpose.
I think BMI is an unreliable testing method of whether you’re healthy or not. Muscle is more dense than fat, so the more you work out, the more you weight. It does not necessarily mean that you are fat. I have a friend who needs to have an overweight BMI to donate blood. It’s ridiculous
I know that i am overweight and this is based on what i observe an extended tummy, large arms and just the sensation of feeling heavier. The BMI also based on my height of 5ft and my weight of 170 (374 kg) pounds stated that as well. I know that most of my weight is fat and as the article mentioned it is in the dangerous areas of the body and this is a cause for concern. I am working to get to an acceptable BMI in the near future. The BMI is scientifically based and is a guide that we can use to keep us along the lines of healthy lifestyle based on out weight to height ratio.
Physical appearance is that of being too stocky and broad. It can take a toll on persons emotionally as the glorification of skinny persons may result in overweight individuals feeling less than appropriate in this day and age.
BMIs really bother me for this reason! I just don’t feel like it’s very accurate. According to my BMI, I’m borderline overweight but I don’t think anyone in their right mind would classify me as overweight.
It’s good to know someone is discussing the gender differences when measuring BMIs. I agree the BMI is just one of the tools used to screen health. But it greater needs fine-tuning because it still fails to reflect ethnic, regional and cultural differences. It also is a system established by men who determined the grading scale, I fear, based upon their preferences primarily.
Quite interesting! I had no idea it was different for females and males-I’ll definitely take this into account next time I get mine measured.
I recently read that, according to the BMI, the majority of female Olympians would be classed as obese! There’s no accounting for muscle mass here, or indeed the fact that we all have different frames. Even though I wear a UK size 10, the BMI has me down as being underweight. Maybe a system based on your relative body proportions would be more useful?
Thanks for this article! I’ve never been much of a fan of using BMI because it doesn’t account for nearly enough factors. Sure, most people can use traditional calculators and trust if it says you’re at a health weight or obese or underweight, but it’s never perfect for athletes or women. At least this addresses some of my worries by addressing a calculator specifically for females.
Thanks for posting this article. I’ve been using the BMI calculation for years as just one component of my fitness evaluation. To me, it’s a lot like weight, in that it’s very easy to measure (just jump on the scale) and provides a concrete number that you can compare to previous results. However, I think it’s more important to be “fit” and that’s much harder to measure and put on a chart. I wish that doctors and other professionals would look at BMI as just one, small component to “health” and take into account how many sit-ups/push-ups/pull-ups I can do or how fast I can run a 5K or how well I can balance on one foot or how far I can stretch. I think that these things are just as important, if not more, than my weight.
Thanks for the article! The BMI concept is a very interesting one, particularly the way that it attempts to put us all in a neat little box. I think that it is definitely oversimplifying the matter, and that in reality, weight is a much more complex and individual phenomenon.
With a system of measurement based purely off weight and height, there are way too many potential avenues for error. Different people’s bodies are made differently, store fat and muscle differently, or are just composed in an entirely different way. However, despite it’s apparent flaws, I agree with you that is a good starting point.
Thank you SO much for posting this! BMI charts are not always reliable. For instance, according to a BMI chart, I am about 10 lbs overweight, but according to a military system which measures almost every limb on your body as well as your neck, waist, etc. I a considered in the perfect range. The BMI does not take into consideration our body fat vs lean fat. I wish doctors relied on it a bit less.
I think that BMI can be incredibly misleading in general, because it often means that if you have a higher muscle mass you come out as overweight, even though you’re probably incredibly fit and healthy as a person. However, you should remember that it is only meant to be a guide, and if you’re the type of person who is so super-fit, you probably wouldn’t need to be calculating your BMI anyway. If you’re overweight, it does give you a decent indication of the kind of weight you should be, but you should never use it as an indicator of general health, nor should it be the only thing that you base it on. You should do other body measurements as well, which can be much more accurate than just your weight alone.
From personal experience (I am studying to be a cook, so we have a class about diets and things like that) I studied the BMI a bit, don’t fully follow it, it’s just a guideline. You should know and see when you’re in bad shape, don’t let a number discourage you 🙂
I have been keeping a check on my BMI for years, but recently my health care provider stated that they don’t believe the BMI is correct and they moved towards the method where you measure your waist instead. According to both I am in the same general weight zone. To me taking your BMI is still a good way of ensuring you’re in an okay weight zone, but I also believe you shouldn’t have your own opinion about your weight being unhealthy or healthy, as we all have unique bodies.
The information provided in this article is very helpful in informing people on the difference between men vs. women BMI. I especially like that the author states there are other tests that should be considered if you fall in the unhealthy BMI ranges. The article helps inform that there are other factors one must consider when determining if you’re healthy or not. Even marathon runners can fall into an unhealthy BMI range while a couch potato fall into a healthy BMI range. BMI measurements do not consider one’s daily activity level.
I’m glad that someone is finally bringing this information to light. As a woman I’ve always known that having my body type judged against a man’s was off. I will admit though, I fall into an unhealthy weight range. That’s why I am here though! Positive life changes!
BMI information is so intimidating for me. I appreciate how this is all broken down; thanks too for the info that 1- this is just one of many different types of tests and 2- where your fat falls is another important thing to check out.
This is a really good point! I actually am at a fine/normal weight according to a standard BMI calculation, but it is easy to see that it is an overly simplistic tool for measuring ‘health’. People’s bodies are shaped differently, it’s simply silly to expect them all to conform to a BMI-directed standard, regardless of frame or muscle composition.
I suspect that a body fat composition test would tell a more interesting story for most people, or at least be a better tool for discerning possible health problems, especially for women (as this article points out!).
I first found out about BMI in highschool but didn’t pay much attention to it. When you’re young you don’t pay mind to things like that usually. I was introduced to it again when I was visiting the doctor a few years ago. I was looking around the patient room and saw the BMI chart hanging on the wall. It took me a few minutes to figure it out but once I did I saw that I was in a good range. Over those past few years I gained a little weight. This summer took a big toll on me because it has been so cold! Spring is finally here now and I am so glad I will get to go play basketball and go swimming!
I do not think that things like BMI calculators are important to know about unless you are a doctor. I remember my BMI when i was in 6tht grade was about 22, but I couldn’t handle being “normal” or slightly above it so I stopped eating. These kinds of measurements can easily calculate into self worth for some people. Once my BMI hit 17 I was happier, but I couldn’t stop losing weight. I have overcome that, mostly, but I do not think it should become another standard to live up to.
I agree that BMI is an estimated measurement. It’s a good thing to know what it is, although it’s not always 100% accurate, it can give you an overall idea of close to where you lie. There are other factors that also play a roll, as in bone weight and muscle weight
I completely agree with you! This was a great article though for pointing out how different the BMI is for females. In high school health classes my BMI showed I was anorexic when really my doctor said I was completely fine and healthy. I am very tall and have a small frame and it’s hard to really account for that when calculating BMI.
As somebody who is a) quite short, and b) quite busty, my BMI always, and I mean always, puts me in the overweight category. However, my measurements are those of a size 8 UK dress so there is no way I’m overweight. It’s all very peculiar.
I’m not helped by the fact I do a lot of weight work to keep toned, so the scales obviously have me heavier due to muscle weight.
All in all, if you have a healthy diet and don’t have any health implications following a trip to the local GP for a check up, BMI is somewhat irrelevant in my opinion.
I’d have to agree with theselittlesteps’ comment above. I always measured on the overweight BMI scale when I was nothing but bones, muscle, and considered quite busty. It was never explained to me clearly and I was made to feel like I was grotesque just because of a number.
I’ve been using BMI calculators online to find out my BMI for school purposes and they all seem to have different answers. The equation above, however, gave the most realistic answer (I think) because it’s the BMI that’s in the middle. All the BMI results I got are either too low or too high and seeing this equation had a middle result, I think I finally know my BMI. Also this was a nice and informative post about BMI calculators for women. Thanks for this!
I’ve never had my BMI measured but I have heard of it. This was really helpful and I’m going to definitely look into what my BMI is to get a better idea of how healthy I am. It was also rather reassuring to see this because I thought I was overweight but by the looks of it, I am considered normal. I’m glad that someone finally covered the basics of BMI in a simple way. Thank you!
We were taught about the BMI scale in school when I was younger but I hadn’t begun using it until I began going for monthly check-ups. Each time, I always measured as slightly overweight, and my doctor had me believe it wasn’t an issue or anything to be overly worked up about but he never explained anything to me in detail, especially how the BMI scale worked exactly and WHY i shouldn’t be worried. I usually find myself watching what I eat and trying to exercise more after each check up, especially since I have thigh and stomach fat. This article explained everything my doctor didn’t and finally put me at ease. Thank you.
thanks for the very driscriptive writing of bmi
I have never felt this was accurate for me. When I was in high school and pretty active, my BMI considered me obese. I was not thin, by any means, but I was definitely not obese. As I got older, I lost a lot of weight. At 5’9″ and 130 pounds it said I was below weight. I felt I was thin, but not underweight. Everyone’s body is different and fitness level should be taken into account as well.
i learned about this in school and they told me that if you want t o gain weight you just have to gain muscles and eat more but if you want to lose weight you would have to go on a diet or do excercise