Body Mass Index Calculator


BMI Calculator


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Learn more about Body Mass Index Calculator

Body Mass Index, or BMI for short, is a word used in almost every human health-related discipline. It is used by personal trainers, nutritionists, doctors, and epidemiologists to classify body weight depending on a person's height and weight.

It is one of the instruments that is utilized in contemporary medicine the most. Despite this, there are many unanswered concerns regarding this measure and it is not generally understood. For instance, BMI frequently fails to take into consideration the difference between lean and fat mass. In any case, as a whole, it serves as a good risk prediction tool.

We will explain what BMI is, how to understand it, and what this figure implies to you and your clients in the sections that follow.

What is BMI?

Body mass index, or BMI, is a metric used in medicine to define a person's healthy bodyweight. In essence, it is a mathematical technique that estimates and classifies a person's body weight using two metrics: height and weight.

Depending on whether you use the metric system or the imperial system, there are two ways to determine BMI. Although imperial can be used, the metric equation is the most popular. After calculating BMI, the result is divided into groups with the goal of defining the person's body weight. Additionally, dependent on age, BMI measures are used differently; those under the age of 2 are considered children, while those above 20 are considered adults.

BMI Chart

bmi chart

BMI Formula

Height and weight are used in the BMI calculation to get an index measurement with no units.

- English BMI Formula (Imperial)

BMI = (Weight in Pounds / (Height in inches x Height in inches)) x 703

- Metric BMI Formula

BMI = (Weight in Kilograms / (Height in Meters x Height in Meters))

If Mary now weighs 160 lb (72.57 kg) and is 5 ft 7 in or 67 in tall, you may get her BMI score using either calculation (1.70 m). BMI equals 25.1.

BMI Interpretations for Children and Teens

Children and teen BMI interpretations Although BMI is computed in the same way for adults and children, it is used in various ways. Unlike BMI for adults, which is not affected by age or sex, BMI for children and teens is.

A percentile chart is used to determine the weight category that pertains to children and teenagers (the one we use in our calculator comes from data obtained from the World Health Organization . The percentile chart contrasts children's and adolescents' BMIs with those of people of the same age and sex. For instance, if children or teenagers have a BMI that is higher than 75% of persons of the same age, they are in the 75th percentile.

Body Mass Index

The Ponderal Index (PI) assesses a person's leanness or corpulence depending on their height and weight, much like the BMI does. The key distinction between the PI and BMI is that the height in the calculation is squared rather than rounded in the former (provided below).

BMI is a valuable tool when analysing huge populations, but it cannot accurately assess an individual's leanness or corpulence. Whereas both the PI and BMI have comparable limitations, the PI is more accurate when used with extremely tall or very short people, while the BMI tends to reflect unusually high or low amounts of body fat for those at the extreme ends of the height and weight continuum.

BMI Limitations

As mentioned above, because BMI doesn't measure body fat directly, it is regarded as a flawed indicator of body fat. In addition, BMI charts do not take into consideration factors that may affect your body fat or muscle, such as age, gender, race, and ethnicity (with the exception of age and sex for children and teenagers). In reality, experts point out that in addition to weight, you need also evaluate the distribution of fat, total muscle mass, age, and gender. Think about these restrictions while determining your BMI.

In adults:

Age, sex, ethnicity, muscle mass, body fat, degree of exercise, and other variables all have an impact on BMI. For instance, an elderly person with a healthy weight who is fully sedentary in everyday life may have a lot of extra body fat while not being overweight. In contrast, a younger individual with a greater muscle composition and the same BMI would be seen as healthy.It is certainly feasible that sportsmen, especially bodybuilders who would be labeled overweight because muscle weighs more than fat, are actually at a healthy weight for their body composition. According to the CDC, typically:

  • With the same BMI, older persons often have more body fat than younger adults.
  • For an equivalent BMI, women typically have more body fat than men do.
  • Due to their large muscle mass, athletes and those who are muscular may have BMIs that are higher.

In children and adolescents:

In children and adolescents:

Children and adolescents can also be affected by the same variables that restrict the effectiveness of BMI in adults. Height effect children's BMI and body fat. In contrast to overweight children, whose BMI may be caused by higher levels of either fat or fat-free mass, obese children's BMI is a better predictor of extra body fat than it is for overweight children.

However, for 90–95 percent of the population, BMI is a reliable indicator of body fat and may be used in conjunction with other measurements to establish a person's health.

Risks Associated with a High BMI

Technique predicting. BMI is one of the most useful risk prediction tools we have in contemporary medicine when we look at human health data. This is particularly true when BMI is used to estimate the likelihood of developing chronic illnesses and many of the major causes of mortality.

Here is a list of the top 5 health dangers of having a high BMI.

  • Cardiovascular Disease: As BMI rises, so does the chance of developing cardiovascular disease. According to certain research, those with the highest BMI categorization are three times more likely than people with normal BMI to experience a cardiovascular incident. However, being in the highest category is not necessary; even people who are "overweight" have a 20% increased chance of experiencing a cardiovascular incident (Khan et al., 2018).
  • One of the most reliable indicators of developing diabetes is BMI. In fact, according to some studies, people with an "overweight" BMI have a roughly six-fold higher risk of developing diabetes than people with a normal BMI.
  • Cancer: Cancer is a complex disease with a wide range of contributing factors. However, some cancer types and BMI are related. For instance, liver and colon cancer rates are higher when BMI is higher.

Shortcomings of the BMI

BMI is frequently criticized for being an ineffective instrument. But frequently, in these talks, it is not clear what BMI is or how to use it most effectively. It's crucial to realize that BMI doesn't distinguish between lean and fat mass and doesn't directly address adiposity (i.e., body fat percentage). However, it is a strategy that relies on enormous sample sizes and is mostly used to forecast risk among large populations of people. As a result, on a population level, BMI may reasonably predict levels of obesity. It is also a useful tool for determining the risk of specific outcomes (for example, mortality, cardiovascular disease, and diabetes).

BMI Calculator For Women

The body mass of women is calculated by dividing the weight in kilograms by the height square in meters.

For example, If a woman weighs 68 kg and is 165 cm long, the mass is calculated as follows:Body mass = weight in kg/length in units of square meters. 68/(1.65)2 = 24.98 and it's a perfect weight, but it is on the edge of weight gain.

BMI Calculator For men

The Measurement of mass is not different for men and women. The difference in fat for both men and women is that if they are similar in mass, the percentage of fat is not equal, but women are more likely to have fat mass.

BMI calculator for children

It is one of the most important assessments used to determine whether children are obese, and also helps to determine the child's growth rate and slow growth.

It is calculated in the same way as BMI in adults. Perfect weight criteria differ between adults and children.