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BMI Calculator for Women – Body Mass Index

Created by Álvaro Díez and Łucja Zaborowska, MD, PhD candidate
Reviewed by Dominik Czernia, PhD and Jack Bowater
Based on research by
Nuttall FQ. Body Mass Index: Obesity, BMI, and Health: A Critical Review.; Nutrition Today; May 2015See 2 more sources
WHO EuropeBody mass index - BMI;Tauqeer Z, Gomez G, Stanford FC. Obesity in Women: Insights for the Clinician; Journal of Women's Health; April 2018
Last updated: Jan 30, 2024


This is the BMI calculator for women, the tool to help you calculate whether you have a healthy BMI for women or an obese BMI. By using the BMI calculation formula, we'll provide an answer to the questions: "What is my BMI?" and "What is a good BMI for women?". We will also explain in detail all of the BMI charts for women, the BMI ranges for women, and explore why it is important to keep a normal BMI.

So read on if you're interested in the BMI scale and learning more about the BMI charts for females. Welcome to our BMI calculator for females!

How to use the BMI for women calculator and interpret the results

In this section, we will teach you how to operate the calculator and interpret its results. First things first, let's answer the question "What is my BMI?" using our calculator:

  1. Input your height. BMI is calculated using meters, but you can use any unit, and the calculator will convert them for you. Make sure to change the unit before you input the value.

  2. Input your weight. Choose the unit as per your requirement.

  3. You will automatically get the results for your BMI and BMI Prime, as well as your WHO BMI category. If that's all you came for, you're done. If not, then stick around.

  4. Now, input your age in years.

  5. Your percentile will be computed and shown. Note, this is calculated using the female population of the USA.

Now you have your results, and it's time to interpret them. Let's start with the BMI Prime and BMI scales. Since they are strongly correlated, it is sufficient to look at one of them, but we show both so you can choose your favorite. Let's say you got a BMI of 29. It will show as "Overweight" with a BMI Prime of 1.16.

Theoretically, this means that you have a little extra weight that you should consider getting rid of if you want to get down to your ideal weight, but before you rush to start a diet, think carefully. First of all, where is that extra weight coming from? Is it body fat or lean mass, or maybe it's just water in your body? Answering these questions correctly is very important and can be tricky since all components have different densities. As a starting point, we recommend using our calculators with underlined words.

Next up, we need to understand the percentile you are placed in. Assuming you are 35 years old, your percentile will be shown as "75th". This means that 75% of the US female population in the age range of 30-39 has a lower BMI than you do. This is generally an indicator of whether things are right or wrong, but as with all BMIs, it's not definitive.

What is the BMI scale and what it measures?

Most of you reading this already know what BMI is, and what it stands for, and you probably have some idea of what a good BMI is. But for those who don't, and for the sake of completeness, we will briefly explain what is BMI, how it is measured, and how you can answer the question "What is my BMI?" even without this BMI calculator for females.

BMI stands for Body Mass Index and is a measurement of the relationship between two prominent body metrics: your weight and height. In particular, BMI is calculated from these two variables by the following BMI calculation formula:

BMI = weight / height²

A crucial remark about this formula is that the units you use DO matter. To discover what is a normal BMI or establish where you place in the BMI range, you should always use the metric system, that is, your weight in kilograms and your height in meters.

BMI is not a definite measurement of anything health-related. However, it is a good statistical measurement so we know if there is anything drastically wrong with our bodies and if we need to worry about health problems. BMI was never designed to be a diagnostic tool, and it has many flaws, which we will talk about later. However, its simplicity makes it very convenient as a first-approach tool to statistically determine if someone is underweight or has an obese BMI, so you can start looking deeper at why that is and if there are any health risks associated.

Normal BMI for women and why separate it from men

When it comes to health and well-being, we are all equally concerned. Why, then, do we make the distinction between men and women? The truth is that, despite all of us being equally involved in health issues, we are not the exact same physically. So when we talk about health issues, it is important to make a distinction between different population groups. As you will see later, it is not only about women vs. men. Within each sex, we also divide them further into age groups to obtain the best comparison possible.

In fact, here at Omni Calculator, we have created 5 different BMI calculators, one for each of the four major BMI groups (children, teenagers, women, and men) as well as a general one, for good measure. If you have landed in this calculator, but you are not an adult woman, you can use other BMI calculators, such as BMI calculator for kids, BMI calculator for teenagers, or BMI calculator for men.

What is a good BMI for women? – WHO and BMI categories

In the year 2000, the World Health Organization (WHO) published a report called Obesity: preventing and managing the global epidemic. On page 9 of this report, there are all the BMI categories recognized by WHO and their BMI ranges. We will use this as a reference from now on. We also include other subcategories that are in agreement with WHO guidelines. These ranges can be plotted on a BMI chart for females and males. You can see the chart in the section below.

There are no distinct charts for males and females because, among other reasons, BMI is just a statistical parameter and doesn't take into account the differences in body shapes and musculature between individuals or groups. Another way to look at it is that even though women tend to have higher levels of healthy body fat, which would make them heavier, men also tend to have higher levels of muscle, which weighs more and contributes to balancing this effect.

Unfortunately, the reality is much more complicated than that, and this dissonance just exposes the problem of BMI when dealing with different body types. We will get into more detail about these problems, as well as discussing the validity of the values for healthy BMI for women and how we can assess our body health better by combining BMI with other parameters.

BMI percentile and its relevance

Let's move on to the BMI percentile results you heard about, which this calculator is able to provide. Percentile is another statistical measurement closely related to the concept of percentage. One way to understand it is to think of them as percentage brackets. Technically you could have 100 different percentiles but to make it easier for ourselves, we typically divide them into groups of more than 1%.

In this calculator, we present data in 9 categories of percentiles, distributed as follows: 0th-5th, 5th-10th, 10th-15th, 15th-25th, 25th-50th, 50th-75th, 75th-85th, 85th-90th, 90th-95th. Each percentile tells you how you relate to the rest of the population in your group. For this calculator, we have selected the female population of the USA and divided it into age groups of ten years, as follows: 20-29, 30-39, ..., 70-79, and 80+.

What the percentile value tells you is where you rank in terms of BMI for women amongst the rest of the American female population. For example, if you're in the 75th percentile, it means that 75% of the female population in the USA has a BMI similar to or lower than yours. This is a comparative tool which means it also has its drawbacks and limitations.

So, when you're having a look at your percentile, just remember that it is skewed towards the condition of the general population. For example, in the USA, women (and men) tend to be overweight, so being placed in the middle (50th) percentile is not exactly a good sign since it probably means you're slightly overweight. Using percentiles together with absolute BMI values (or even with BMI Prime for women) gives you more information about your current state.

We have just sneakily dropped a mention about BMI Prime, which is a new term. Don't worry; we won't leave you hanging; let's explain it and its relevance.

BMI chart for women and BMI Prime

BMI Prime is a term often mentioned in BMI articles that might seem confusing at first glance. It typically ranges from 0.5 to 2, while BMI itself has values between 15 and 40. However, they are both strongly correlated. BMI Prime is no more than the ratio of the actual BMI to the ideal BMI for women. The value for a healthy or normal BMI for women is 25, the same as for men.

What is the advantage of the BMI Prime scale over the normal BMI scale? As long as you know what it means, BMI Prime will not only answer the question "What is my BMI?" but it will also answer the questions "What is good BMI?" and "Is my BMI good?" at the same time. By having a number that compares the healthy BMI for women with your actual BMI, you get double the information in just one number.

An ideal BMI Prime is around 1, which corresponds to a BMI of 25. The margins are narrow since we are talking about small numbers, so even though 1.5 sounds close enough to 1, it corresponds to a BMI of 37.5, which means you have "Obese Class II" or "Severely obese" according to WHO BMI categories.

Another way to compare your BMI and determine whether you have a healthy BMI, or at least a normal BMI, is to look at the BMI chart for women. Below is said BMI chart for females and males. It is conveniently color-coded to separate the regions of healthy BMI from those that are risky or dangerous.

Chart showing BMI ranges for women

To use this BMI chart, please follow these steps:

  1. Find where your BMI is located in the BMI chart for women. You can either use the calculated BMI or your weight and height.
  2. With the help of the legend and the colors in the chart, assess how healthy your BMI is.
  3. If necessary, devise a plan to change your BMI to healthier levels. If it's already healthy: Congratulations!

We have mentioned that the first step is to calculate your BMI as female, and we showed you how to use the BMI calculation formula to do that by hand. However, we haven't really shown you how to use the BMI calculator for women, so let's take a closer look at that now.

Healthy BMI for women: how bad is to be in the obese BMI range?

We will now show you some data from a correlational study between the BMI for women and the mortality rate. As we can see, a strong correlation exists between having a not ideal BMI for women and a high mortality rate. Does it mean that an unhealthy BMI kills? Well, we do not know for certain since correlation doesn't imply causation, but it would seem that it is much safer to have a normal BMI for women (18.5-25), which shouldn't come as a surprise.

Chart showing the correlation between BMI for women and mortality rates

What is more surprising is the strong correlation at a slightly unhealthy BMI. It could be totally possible that a slightly high BMI causes a higher risk of death, but given the variations in BMI due to many different factors, there's another explanation that seems more plausible. BMI is an indicator that works both ways: women with normal BMI tend to be healthy, and healthy females tend to have normal BMI.

For example, as we age, our metabolisms degrade, and it becomes much easier to put on weight than it was before. If you think about it, it's much harder to find an old person with a healthy weight. People tend to be overweight or underweight as they grow up, compared to their younger years. In any case, it is much better to play it safe and try to stay in an ideal and healthy BMI range for women since there's nothing to win by having extreme BMI values, and there's a lot to lose.

Also, if you are interested in body fat measurements, check out our other calculators, such as skinfold body fat calculator and fat-free mass index calculator.

Differences between male and female BMI percentiles

It is time to take a look at the differences in BMI between men and women beyond the body composition we have mentioned before. The first thing to note is the difference in body type, not only between men and women but also within those groups. If you look at all the men in the world, their general body shape doesn't really vary that much, except for the proportion of fat and muscle.

However, if you look at women, their body shapes change dramatically, even among people with the same proportions of body fat and muscle. For example, the bust size, shape, and proportion between hips and waist. Even women's legs tend to differ much more from one female to another than they do for men. What does this mean for BMI charts for women? It means a big disparity.

If we look at the BMI ranges for women, they are the same as for men because those are made in a purely theoretical way. If instead, you look at the percentile BMI ranges, the story changes a lot. The spread of BMI values in women is much greater than that of men. Let's look at an example to understand this better.

Let's compare the values for the 5th and 95th percentiles of BMI for women to those for men. There is something surprising. Across all age groups, the 5th percentile limit is lower for women than for men, but, at the same time, the 95th percentile limit is also higher for women. So the distribution of BMI for women is not biased towards higher BMI or lower BMI, but it is more evenly distributed than for men.

What this means is that at the extreme values of BMI ranges, there are proportionally more women than men at those extremes. There are two possible reasons for this, and it is likely they are both at play. First of all, it could be due to the above difference in body shapes. Due to the wide range of female body types, women have a much larger range of BMIs that could still be considered healthy, whereas the range is much narrower for men.

The other possibility comes from societal pressure. It is unarguable that women are treated differently than men in our society, from the gender pay gap to physical appearance. And it is this physical appearance pressure that could possibly be at the root of these extreme cases. Some women pathologically try to get an 'ideal weight' that is far too low for it to be healthy. While others might feel like this is all a big lie and that there is nothing wrong with having an obese BMI. Both approaches are seriously dangerous and potentially life-threatening. So we need to grow, as a society, towards a more educated view of body weight where health is more important than looks and unattainable (fake) standards of beauty.

Making of the BMI calculator for women

One day, Álvaro, our fitness enthusiast, thought a gender-specific BMI calculator would help many people and discussed it with Łucja. She acknowledged that women and men tend to have different body compositions, like where fat is stored and how much muscle mass they have. This gave them the brilliant idea to make a BMI calculator for women. Such a tool could provide our female users with insights that fit their bodies' unique makeup, helping them understand their health in a way tailored just for them.

Álvaro Díez is a fascinating individual with eclectic interests and relentless optimism, defining his unique approach to life and learning. He is a health enthusiast passionate about biking, reflecting his adventurous spirit and commitment to a lifestyle that values sustainability and physical well-being. In many ways, Álvaro exemplifies the power of curiosity and the importance of sharing knowledge.

Łucja Zaborowska's profile stands out for her exceptional achievements and dedication to medicine. An honored graduate from the prestigious Jagiellonian University Medical School, she has shown remarkable academic excellence and a deep commitment to advancing medical ethics and women's health, tackling some of healthcare's most critical challenges.

Together, the dynamic duo brought us the BMI calculator tailored explicitly for women that acknowledges the unique aspects of female health and physiology.

We ensure our tools are based on authentic information and proper research. After an expert makes the calculator, another expert in the field reviews it thoroughly. Then, a native language speaker proofreads the content, ensuring further refinement; only then is the tool released for our users. To learn more about our commitment to quality, please refer to our Editorial Policies page.

FAQ

What is the best BMI for women?

The range of normal BMI values for women is 18.5-25. Above 25, you're overweight; below 18.5, you're underweight.

Is a BMI of 20 skinny for women?

Yes. The BMI of 20 lies in the normal range of female BMI; in fact, it lies in the lower region of the normal range, i.e., on the lean side. Congratulations, and try to keep this BMI!

Is a BMI of 23 good for a woman?

Yes, a BMI of 23 lies within the normal range of BMI for women. While it is the higher region of the normal range, you don't need to lose weight but make sure not to gain!

How do I calculate BMI for women?

To calculate female BMI, follow these steps:

  1. Determine you're weight and height.

  2. The weight must be in kilograms and height in meters. If needed, use an online converter.

  3. Apply the BMI formula:
    BMI = weight / height²

  4. To interpret your result, compare it with the normal BMI range for women, which reads 18.5-25.

Álvaro Díez and Łucja Zaborowska, MD, PhD candidate
Height
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in
Weight
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BMI
BMI Prime
Age
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So you are...
Percentile
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