Body mass index is a ratio of a person's weight to height. Thanks to simple calculations, doctors determine the lack or excess of muscle and adipose tissue in the body, which allows timely start of weight correction procedures. With the calculator below, you can also find out how your weight matches your height. This will help you choose a diet, if necessary, normalize physical exercise and so on.
Body mass index formula
In 1869, the eminent Belgian mathematician/sociologist Adolphe Quetelet first proposed a formula for measuring body mass index. It was he who considered that in order to derive a coefficient by which it is possible to assess the fullness / thinness of a person, it is enough to divide his weight in kg by the square of height in meters. In other words, to find out the body mass index, the formula looks like this:
Let's try to calculate: suppose that a woman addressed us, whose height is 1.64 m, and her weight is 75 kg. To calculate her BMI, you need 75 / 1.64 * 1.64 = 27.89. As you can see in the table, this is overweight. That is, our hypothetical lady urgently needs to reconsider her lifestyle or nutrition system.
However, this BMI result should not be considered always correct. Indeed, when calculating, we did not take into account what kind of lifestyle a woman leads (suddenly, is she a professional athlete - a wrestler or boxer with well-developed muscles?), And we also did not take into account the age of the lady.
Therefore, the Adolf Ketele formula for measuring body mass index can only be used to obtain primary coefficients. To do this, use a calculator.
If the result of the calculations shows that it is time for you to lose weight, use the advanced body mass index calculator.
Body mass index norms
As already mentioned, the norm of the body mass index is a conditional value. So for people with an asthenic physique, a BMI of 24 points can mean pre-obesity, and for a professional athlete and a BMI of 27 can be the norm. However, you can still tentatively rely on indicators approved by WHO.
I would like to note that the norm of the body mass index is calculated not only for adults, already physically formed men and women, but also for children. It is very important to monitor the weight of the child, since the deficiency and excess of mass can lead to serious illnesses and deviations in physical development.
How to calculate your ideal weight?
Knowing the norm of the body mass index, you can calculate your ideal weight. To do this, you should multiply the optimal BMI result (19-24) by the square of your height in meters. Do the calculations manually or use this calculator.
Ideal weight is an average standard that is calculated based on data from a large number of people. But all people are different. Lifestyle, food culture, nationality and body type - all this affects the ideal weight. For example, the normal weight of people with a strong physique will be 2-3% higher than that of people with an average body. And the norm for thin people is 3-5% less. Therefore, it is not necessary to strive specifically for the ideal weight, which shows weight calculator. It is enough if your weight is within the calculated range.
Beyond the weight calculator calculates BMI- body mass index (ideal weight), which is widely used to determine the degree of correspondence between body weight and height.
How to calculate your ideal weight (BMI) yourself
BMI \u003d M: R 2, where
M - body weight in kg
P - height in meters
An example of calculating the body mass index: M (weight) - 78 kg, P (height) - 1.68 m
BMI = 78: 1.68 2 = 27.6
From the table below, you can see that BMI = 27.6 corresponds to overweight.
Table of interpretation of BMI indicators
In the case of a strong deviation from the norm, it is time to seriously think about correcting your weight. With reduced weight, dystrophy develops. In the modern civilized world, its cause is usually intentional malnutrition. The desire to have is unnatural slim figure can result in both psychological and physical health- the ability to work decreases, the skin dries, hair falls out. All this comes from a lack of substances necessary for the body.
However, their excessive excess also does not lead to anything good. A huge number of people suffer from obesity. Excess weight greatly increases the risk of kidney stones and gallbladder, joint deformities, impotence, myocardial infarction and many other diseases. The whole body works with overload, moving masses of fat in space that are not provided for by the design. human body. Not surprisingly, the life expectancy of obese people is on average 6-8 years less than that of the rest.
If explained in simple, accessible language, then the body mass index shows the correspondence of a person’s height and weight. It clearly shows the lack of weight or the presence of obesity. That is why such a simple and affordable calculation of BMI is very popular not only in everyday life, but doctors also actively use it.
Of course, relying only on this calculation, one cannot make medical diagnoses. The value of the body mass index is rather an average indication, since it does not take into account all the nuances of the state of the body of a particular person.
But, for the sake of justice, it is worth noting that the human body mass index calculated by the formula can tell you about the need to urgently consult a doctor to develop special program for weight loss, if your indicators are "going wild".
Body mass index formula
| BMI= | Weight, kg) |
| Height (m) 2 |
We were able to calculate the body mass index for women, and now we need to analyze the data obtained. From a medical point of view, normal weight is considered to be weight in a fairly large range of values, since it takes into account all the characteristics of the human body: its gender, age, physical activity, etc.
Let's calculate your body mass index and analyze the results.
Online calculator for calculating BMI
Weight
Height
The result obtained is interpreted as follows:
Severe underweight
If after the calculations you got a result less than 16.5 and at the same time you are not considered one of the thinnest fashion models in the world, this is an occasion to seriously think about your health. After all, a body mass index below 17.5 kg / m² is one of the diagnostic indicators of anorexia.
Underweight
An indicator from 16 to 18.5 kg / m² indicates a lack of body weight. If everyone around tells a girl that she is very thin, she should determine her BMI, and if it is within this indicator, then in no case should she diet. After all, too little weight causes a host of health problems, from anemia and bone loss to problems conceiving a child.
normal body weight
The most fortunate are those whose BMI is in the range of 18.5-24.99 kg / m². After all, this is an indicator of normal weight. Thinking about following a not too rigid diet is only for those whose weight is approaching the upper limit of the norm, and the waist circumference in women at the same time exceeds 81 cm, and in men - 94 cm. The last figures indicate excess weight.
Overweight (pre-obesity)
A body mass index of 25 to 29.99 kg/m² indicates the presence overweight. This degree is also called preobesity. This category includes, for example, women who, with a height of 160 cm, weigh 64-65 kg. They look plump and this does not seem to be a problem.
However, from a medical point of view, they are already at particular risk for the development of diseases caused by overweight, especially if they have a waist circumference of more than 80 cm. The closer a person approaches the upper limit of the body mass index, the higher the risk of serious diseases such as cardiovascular disease, metabolic syndrome, diabetes mellitus.
Obesity
Indicators from 30 to 34.99 kg / m² are a signal of danger to health, because they indicate the presence of obesity of the first degree. To reduce body weight in this situation is necessary, because obesity is not a beauty problem, but a serious illness. In the first degree of obesity, cardiovascular disease, type 2 diabetes and hypertension are real threats, and the larger the waist, the higher the risk.
A body mass index of 35 to 39.99 kg/m² is indicative of second-degree obesity, which doctors associate with a very high risk of developing serious illnesses.
If the body mass index is 40 kg / m² or more, this is obesity of the third degree. Such an indicator indicates a threat not only to health, but also to life.
How to calculate body mass index: Video lesson
Body mass index is the optimal ratio of weight and height. Everyone wants to be slim and beautiful, but the problem of overweight for a modern person is one of the most pressing today. How to solve it?
Today we are witnessing a real fitness boom. Everyone tries to "build" their body in full accordance with the canons of beauty. Physical education tightens worse than drug addiction, so many do not get out of the gym at all, furiously burning every extra gram, as it seems to them.
But is it right? Excess weight, of course, becomes the cause of many diseases of the musculoskeletal and cardiovascular systems. However, the lack of weight leads to the same result.
How to become perfect? Everyone knows: we take height in centimeters and subtract 110 from this figure. What happened is optimal weight.
For example, a woman with a height of 176 centimeters weighs 66 kilograms. She is perfect: 176 - 110 = 66.
But doesn't this approach seem too exaggerated? After all, only one parametric indicator is used - growth. And people are different from each other - age and physique are different for everyone. To take into account all these indicators, you need to apply a different formula. It is called the body mass index (BMI) and indicates the optimal ratio of height and weight.
This is what the body mass index looks like (table for women).
| Height in cm | Age | ||||
|---|---|---|---|---|---|
| 20-29 | 30-39 | 40-49 | 50-59 | 60-69 | 150 | 48.9 | 53.9 | 58.5 | 55.7 | 54.8 |
| 152 | 51.0 | 55.0 | 59.5 | 57.6 | 55.9 |
| 154 | 53.0 | 59.1 | 62.4 | 60.2 | 59.0 |
| 156 | 55.8 | 61.5 | 66.0 | 62.4 | 60.9 |
| 158 | 58.1 | 64.1 | 67.9 | 64.5 | 62.4 |
| 160 | 59.8 | 65.8 | 69.9 | 65.8 | 64.6 |
| 162 | 61.6 | 68.5 | 72.2 | 68.7 | 66.5 |
| 164 | 63.6 | 70.8 | 74.0 | 72.0 | 70.7 |
| 166 | 65.2 | 71.8 | 76.6 | 73.8 | 71.4 |
| 168 | 68.5 | 73.7 | 78.2 | 74.8 | 73.3 |
| 170 | 69.2 | 75.8 | 79.8 | 76.8 | 75.0 |
| 172 | 72.8 | 77.0 | 81.7 | 77.7 | 76.3 |
| 174 | 74.3 | 79.0 | 83.7 | 79.4 | 78.0 |
| 176 | 76.8 | 79.9 | 84.6 | 80.5 | 79.1 |
| 178 | 78.2 | 82.4 | 86.1 | 82.4 | 80.9 |
| 180 | 80.9 | 83.9 | 88.1 | 84.1 | 81.6 |
| 182 | 83.3 | 87.7 | 89.3 | 86.5 | 82.9 |
| 184 | 85.5 | 89.4 | 90.9 | 87.4 | 85.8 |
| 186 | 89.2 | 91.0 | 92.9 | 89.6 | 87.3 |
| 188 | 91.8 | 94.4 | 95.8 | 91.5 | 88.8 |
| 190 | 92.3 | 95.8 | 97.4 | 95.6 | 92.9 |
What does BMI depend on?
It should not be assumed that the BMI table for women can replace the beauty formula. People with the same BMI look different, which, in general, is logical: each organism has individual anthropometry. Physiologists distinguish three types of physique.
- The thin-boned type is easy to identify by conspicuous long legs and arms, a thin neck.
- The normo-bone type is people with familiar, one might say, classical proportions.
- The broad-boned type is defined by a high diaphragm and broad chest and shoulders.
Determining your body type is very easy: you just need to measure the circumference of your wrist just below the bone. The norm for the normo-bone type will be from 16 to 18 cm. If the result is less than 16 cm, then you are a hyposthenic (thin-boned type). If you are over 18, you are hypersthenic, or a person with a large-boned body type.
Naturally, for different body types, the ideal weight will be different. A mass that is normal for, say, a hypersthenic will be insufficient for a person with a normal-boned physique.
BMI for women, taking into account age, will also differ from the generally accepted one. With age, the body no longer burns fat so intensively, so the older you get, the more difficult it is to get rid of the layer on the hips or abdomen. Therefore, when calculating BMI, it is necessary to take into account how old a person is.
Why you need to know BMI
This value is necessary for those who follow their figure. Of course, you can exhaust yourself with diets or exhausting workouts - to each his own. But to what weight limits do we need to keep the diet? After all, it’s so short to lose weight and to anorexia. The answer to the question will be BMI: this is the indicator that you need to strive for.
How to calculate BMI
It was developed by the Belgian anthropologist Quetelet in the middle of the 19th century. However, modern doctors still use it, determining the level of obesity or dystrophy in their patients. Naturally, over the course of two centuries, the Quetelet method has undergone certain adjustments; other scientists have created their own calculation tables based on BMI. However, all the changes were only beneficial, since they allow you to most accurately calculate the ideal weight for each person.
Quetelet proposed to use a more complex formula to calculate the optimal mass: the weight must be divided by the square of height in meters. The result is a body mass index, the value of which corresponds to a certain state of the body - a mass deficit, a norm or its excess:
- Weight deficit - from 18.49 and below (below 16 - a critical deficit).
- The norm is from 18.50 to 24.99.
- Overweight - from 25 to 29.99 (from 30 and above - obesity).
That is, for the same woman (176 cm, 66 kg), the body mass index will be: 66: 1.762 = 21.35. Her BMI is within the normal range. But BMI by age is not taken into account in the Quetelet formula.
Many other doctors offered their BMI calculation:
- BMI according to Brokk. From height in cm, you need to subtract 110, multiply the resulting number by 1.15.
For example, we can take a woman already familiar to us with parameters of 176 cm and 66 kg: (176 - 110) × 1.15 = 75.9. It turns out that according to Brokk, our woman has a lack of weight.
- BMI according to Lorenz. Subtract 100 from height in cm. Then subtract 150 from height in cm and divide by 2. After that, subtract the second from the first result.
Difficult? Let's explain using the example of the already mentioned woman: (176 - 100) - (176 - 150) / 2 = 63. That is, according to Lorenz, our friend has three extra pounds.
Let's try to demonstrate on the example of our old friend. First, let's determine her height in inches: 176 / 2.54 = 69.3. Now we calculate BMI: 45.5 + 2.3 × (69.3 - 60) = 66.89.
- BMI according to Humvee. The calculation formula is almost the same as the previous one: 45.5 + 2.2 × (height in inches - 60).
According to this formula, the optimal weight for our woman will be 45.5 + 2.2 × (69.3 - 60) = 65.96. As you can see, there is a difference, but very small.
- BMI according to Kref. This technique allows you to calculate the body mass index by age and body type. To calculate BMI, you need to take several steps:
- Age must be divided by 10.
- You need to subtract 100 from height.
- Add up the results and multiply the resulting figure by 0.9.
- What happened, multiply by the coefficient of measurements of the wrist.
The coefficients, depending on the circumference, are as follows:
- less than 15 cm - 0.9;
- up to 17 cm - 1;
- more than 17 - 1.1.
Let's explain with an example. Let's say the woman we talked about above is 40 years old, wrist circumference is 16 cm. Then her ideal weight will be: (176 - 100 + (40 / 10)) × 0.9 × 1 = 72 kg.
- BMI according to Egorov-Levitsky. The authors of the book "Obesity", Professor Egorov and Doctor of Medical Sciences Levitsky, suggest not to calculate anything, but to check your weight according to the table they developed.
| Height in cm | Men | Women | |||
|---|---|---|---|---|---|
| Asthenics | Normostenics | Hypersthenics | Asthenics | Normostenics | |
| 148 | 42,0 - 44,8 | 43,8 - 48,9 | |||
| 150 | 42,7 - 45,9 | 44,5 - 50,0 | |||
| 152 | 43,4 - 47,0 | 45,6 - 51,0 | |||
| 154 | 44,4 - 48,0 | 46,7 - 52,1 | |||
| 156 | 45,4 - 49,1 | 47,7 - 53,2 | |||
| 158 | 51,1 - 54,7 | 53,8 - 58,9 | 57,4 - 64,2 | 46,5 - 50,2 | 48,8 - 54,3 |
| 160 | 52,2 - 55,8 | 54,9 - 60,3 | 58,5 - 65,3 | 47,6 - 51,3 | 49,9 - 55,3 |
| 162 | 53,2 - 56,9 | 55,9 - 61,9 | 59,6 - 66,7 | 48,7 - 52,3 | 51,0 - 56,8 |
| 164 | 54,3 - 57,9 | 57,0 - 62,5 | 60,7 - 68,8 | 49,8 - 53,4 | 52,0 - 58,2 |
| 166 | 55,4 - 59,2 | 58,1 - 63,7 | 61,7 - 69,6 | 50,8 - 54,6 | 53,3 - 59,8 |
| 168 | 56,5 - 60,6 | 59,2 - 65,1 | 62,9 - 71,1 | 52,0 - 56,0 | 54,7 - 61,5 |
| 170 | 57,9 - 62,0 | 60,7 - 66,7 | 64,3 - 72,9 | 53,4 - 57,9 | 56,1 - 62,9 |
| 172 | 59,4 - 63,4 | 62,1 - 68,3 | 66,0 - 74,7 | 54,8 - 58,9 | 57,5 - 64,3 |
| 174 | 60,8 - 64,9 | 63,5 - 69,9 | 67,6 - 76,2 | 56,3 - 60,3 | 59,0 - 65,8 |
| 176 | 62,6 - 66,4 | 64,9 - 71,3 | 69,0 - 77,6 | 57,7 - 61,9 | 60,4 - 67,2 |
| 178 | 63,6 - 68,2 | 66,5 - 72,8 | 70,4 - 79,1 | 59,1 - 63,6 | 61,8 - 68,6 |
| 180 | 65,1 - 69,6 | 67,8 - 74,7 | 71,9 - 80,9 | 60,5 - 65,1 | 63,3 - 70,1 |
| 182 | 66,5 - 71,0 | 69,2 - 76,3 | 73,6 - 82,7 | 62,0 - 66,5 | 64,7 - 71,5 |
| 184 | 67,9 - 72,5 | 70,7 - 78,1 | 75,2 - 84,5 | 63,4 - 67,9 | 66,1 - 72,7 |
| 186 | 69,4 - 74,0 | 72,1 - 79,0 | 76,7 - 86,2 | ||
| 188 | 70,8 - 75,8 | 73,5 - 81,7 | 78,5 - 88,0 | ||
| 190 | 72,2 - 77,2 | 75,3 - 83,5 | 80,3 - 89,8 | ||
| 194 | 75,1 - 80,1 | 78,9 - 87,0 | 83,2 - 93,4 | ||
The body mass index for men is the most important indicator that clearly demonstrates the correspondence between a person’s height and weight. Deviations are indicated by going beyond the lower and upper limits of the indicator. Exceeding the norm signals the danger of obesity, lowering - about the problems of the digestive tract, about an insufficiently balanced diet. Therefore, absolutely all people need to calculate their body mass index. It is very important that the indicator corresponds to the norm.
Quetelet formula
For the first time, the formula for calculating body mass index (BMI) was developed in the 19th century by the Belgian scientist Adolf Quetelet. More than a decade has passed, and the formula is still actively used. The formula for calculating body mass index shows the ratio of body weight (M), measured in kilograms, to the square of height (P), measured in meters:
BMI=M(kg)/(P*P)
BMI=93/(1.88*1.88)=26.31
The Quetelet formula is often used by doctors in order to identify pathologies associated with excess or lack of body weight, in order to further select the optimal procedures. In some cases, deviations are critical and require more serious treatment.
The thickness is still inferior to the growth ...
What the numbers say
Table of deviations according to the Quetelet formula:
Deviation from the norm does not always indicate a violation of the state of health. The diagnostic method will be absolutely useless if the indicator is calculated for a teenager or an athlete. For a growing organism, the standard will be lower, and for an athlete - higher. Also, the method does not work for pregnant women.
In addition, it is necessary to take into account the type of physique. Allocate:
- asthenic (ectomorphic) type;
- normosthenic (mesomorphic) type;
- hypersthenic (endomorphic) type.
Asthenics, as a rule, are above average height, narrow shoulders and wrists. Ectomorphs have little body fat, muscle rather underdeveloped. A man of an asthenic body type is slender, which is expressed in elongated proportions. It is very difficult for such people to build muscle, but it is easy to maintain a normal weight.
Men with a normosthenic (mesomorphic) body type usually have a strong skeleton and developed muscles. Excellent proportions give good inclinations for having an athletic male physique. Usually normosthenics are broad-shouldered, have a protruding chest, dense torso and narrow waist. Limbs in mesomorphs of medium length, adipose tissue weakly expressed. Regular training allows such people to achieve without exhausting labor good results, easy to gain or lose weight.
Representatives of the hypersthenic (endomorphic) body type often have an obese figure, short limbs and neck. Hypersthenics constantly need to monitor a balanced diet, because excess weight is easily gained, but it is very difficult to lose it.
An easy way to find out your body type is to measure your wrist. To do this, you need to grab it with your thumb and forefinger in the narrowest place. With an asthenic body type, the fingers overlap each other, with a normal body type they barely touch, with a hypersthenic type, it is impossible to connect the fingers around the wrist.
Table of BMI parameters for different body types:
Thus, the boundaries of normal indicators for asthenics are shifted to a smaller side, and for hypersthenics - to a larger one.
When evaluating the results of the body mass index, the age of the man must be taken into account.
Table of BMI parameters for different age categories:
Brocca's formula - an alternative method for calculating BMI
Paul Brokk, a famous French anthropologist and surgeon, developed in the 19th century. alternative method for calculating BMI. As a basis, the scientist took information about the age of the subject, body length and body type. Calculating your ideal weight is not difficult, you don’t even need a calculator. You need to find the indicator in the table according to your height and age, and then subtract it from the height (P).
Parameter table ideal weight for different age categories according to Brokk:
Table of parameters of the ideal weight, taking into account the height of a person:
On the way to fix
Excess weight increases the risk of developing diabetes mellitus, cardiovascular diseases, contributes to oppression respiratory system, immune suppression, development of erectile dysfunction, infertility. A sharp decrease in body weight also has a very negative effect on the health of the stronger sex, manifesting itself in such unpleasant consequences as a weakening of the body's defenses, susceptibility to viral diseases.
In pursuit of the ideal...
First of all, it must be remembered that even people with normal index body weight requires regular exercise, balanced diet, as well as adherence to the regime of sleep and rest. If the BMI is close to normal, then simple rules reference healthy lifestyle life needs to be focused.
If you are underweight:
- increase the number of meals;
- eat more protein foods;
- include in the plan sports events strength exercises.
- gradually reduce the calorie content of foods;
- gradually reduce portions of food and the frequency of meals;
- eat more healthy foods, such as cereals, fruits, vegetables;
- exercise regularly.
If the indicator is significantly higher or lower than normal, you should consult a doctor to reduce the risk of complications.
For good health and good health physical form you need to watch your weight. Knowledge of the formulas for calculating the body mass index, the features of the interpretation of the results allows you to control own weight and keep it within the normal range.