BMI Formula Chart

Use the Calculator

It is possible to calculate a person’s BMI based on their weight and height using the BMI Calculator. Determine your body mass index (BMI) and the appropriate BMI weight range for your height. You can also determine the healthy weight range for your height by doing this.

Enter your weight in pounds, stones, or kilograms to get your BMI. Inches, feet and inches, meters, or millimeters can be entered.


Definition of BMI

An individual’s BMI is based on their weight in kilograms divided by their height in meters. The unit of measurement is kilograms per square meter, which is equivalent to pounds per square inch. Underweight, normal, overweight, and obese weight categories are all represented by numerical BMI values.

In order to gauge a person’s overall health, BMI is used. Being overweight or underweight increases a person’s risk for a variety of health issues, according to the Centers for Disease Control and the World Health Organization. Health care providers can use BMI to have a more unbiased conversation with their patients about their weight.

BMI Formula Chart

To Calculate BMI, there are the most popular 2 formulas that can be used. People used these formulas several years ago and still now they have been using the formulas. Here are 2 Units:

1. Metric Unit

2. US Unit

  • Metric units: BMI = weight (kg) ÷ height2 (meters)

Weight in kilograms divided by height in meters squared is the metric system’s formula for calculating BMI. Weight in kilograms divided by height in centimeters squared, multiplied by 10,000, can be used as an alternative calculation formula because height is frequently measured in centimeters.

BMi calculating formula with apple
  • US units: BMI = (weight (lb) ÷ height2) * 703 (inches)

To find your BMI, multiply your weight in pounds by your height in inches, then multiply that result by a conversion factor of 703 to arrive at your BMI. Weight (lb) divided by height (in) squared, multiplied by 703, then rounded to the nearest tenth using a pocket calculator equipped with a square function.

Ponderal Index

The Ponderal Index (PI), like the BMI, measures a person’s leanness or corpulence depending on their height and weight. The key difference between the PI and the BMI is that the height is cubed rather than squared in the formula (provided below). While BMI is beneficial when assessing large populations, it is unreliable when assessing individual leanness or corpulence. Although both have flaws, the PI is more accurate when used with very tall or short people, whereas the BMI tends to reflect abnormally high or low body fat levels for those at the extremes of the height and weight continuum. The following is the equation for calculating an individual’s PI using USC, using a 5’10”, 160-pound person as an example:

USC Units:

  • PI = height (in) / ∛mass (lbs)= 70 / ∛160 = 12.89 (in/∛lbs)

SI, Metric Units:

  • PI = mass (kg) / height3 (m) = 72.57 / 1.783  = 12.87 (kg / m3 )

BMI Catagories

BMI range

BMI Chart for Children and Teenage (Aged 2 to 20 years)

The body mass index of children varies. It is calculated in the same manner as an adult’s, but the results are then compared to those of other children of the same age. Utilizing percentiles for children of the same gender and age as an alternative to utilizing set standards for underweight and overweight children

BMI Chart for Boys

BMI Chart for Girls

Underweight individuals have a body mass index (BMI) that falls below the 5th percentile, whereas obese individuals have a BMI that exceeds the 95th percentile. Children that are overweight have a body mass index that falls between the 85th and 95th percentiles.

BMI Chart for Adults & Seniors

As a result, the Smart BMI data is based on the most up-to-date studies available, with an emphasis on providing the most accurate results. There are fewer and consequently less reliable data for certain demographic groups, such as the elderly.


The Benefits and Drawbacks of BMI

The Body Mass Index (BMI) is an easy method for estimating total body fat. It is easy to use, it does not cost very much, and it does not require much preparation. As a consequence of this, it is a simple method for locating a person who may have a health concern that merits further investigation. In addition to this, it is universally utilized by medical professionals all over the world in the conduct of research.

Having said that, it does suffer from a number of severe shortcomings. To begin with, it cannot be utilized to diagnose health problems; rather, it can only uncover potential warning signs.

Because the BMI does not take into consideration the following characteristics, it is also possible for a considerable number of persons to have a false positive result from using it.

Mass of Muscle

The density of bone and muscle is greater than that of fat. The only two measurements that are utilized in the BMI calculation are a person’s height and weight, which means that it may give an inaccurate reading for persons who have a lot of muscle mass, such as athletes. 3

It is also possible for it to underestimate body fat in individuals who have a very low muscular mass.


The body mass index does not take into consideration a person’s race, which is an important factor that can affect the health risks associated with obesity. As well as body composition, which refers to the percentage of total body weight that is comprised of fat as opposed to lean muscular tissue.

When compared to Europeans of the same weight, for instance, Asians and South Asians have a greater proportion of body fat than Europeans do, but Blacks have less body fat and more muscle at the same weight as Europeans do. Asians and South Asians also have a higher percentage of body fat than Europeans do.

For this reason, a number of industry professionals are increasingly arguing in favor of individualized cutoffs for certain categories.

Predetermined Gender

People who are born female typically have a higher percentage of body fat compared to men. The BMI does not take this discrepancy into consideration. As a result, a woman may have a BMI that places her in a group considered “safe,” yet she may still have amounts of body fat that pose a potential threat to her health.


It’s possible that the normal BMI ranges can’t effectively forecast the health hazards faced by younger or older people.
5 For instance, having a body mass index (BMI) that is below 23, which is considered to be within the so-called normal range for adults, is connected with a higher risk of death, whereas having a BMI that is within the “overweight” range is not.

The Manner in Which Fat Is Distributed

There is some evidence to show that the location of fat on the body also matters. People who have what is known as a “apple” body shape, where most of their weight is carried around the center, have greater health risks than those who have a “pear” shape (i.e., those who accumulate weight in the hips and thighs).

Alternatives to BMI

Because of these problems, some people have advocated for BMI to be retired. In spite of the fact that its drawbacks are well acknowledged, BMI is still used, in part because it is easy to apply.

Other approaches can be used in place of or in addition to BMI for measuring body fat or determining a person’s risk to their health, and these methods can be utilized when desired or judged necessary.

These are the following:

The amount of fat that is carried around the center of your body, as measured by your waist circumference, can raise the risk that you will develop type 2 diabetes and heart disease.

  • Waist circumference: The risk rises for women when their waist circumference is larger than 35 inches, and it rises for men when their waist circumference is greater than 40 inches. It is currently being suggested by a number of specialists that waist circumference is a more accurate measurement for all people, but that it may be especially beneficial in assessing the health risks faced by persons of color.
  • Waist-to-hip ratio: The proportion of waist to hips: The information that can be gained concerning prospective health hazards can be obtained by dividing the circumference of your waist by the circumference of your hips. For women, a reading of 0.9 or higher suggests an increased risk, while for men, a measurement of 1.0 or higher indicates an increased risk. Calipers are a device that measures the thickness of the skin, and hence can be used to provide an estimate of the proportion of body fat a person possesses.
  • Skin-fold measurements: After collecting data from a variety of points across the body, it is entered into a mathematical model. 10 Intelligent bathroom scales are now available, and some of them can calculate your body fat percentage.
  • Smart scale: These scales calculate your body fat percentage by passing a safe electrical current through your body when you stand on them. Take note that the technology utilized by smart scales necessitates a body that maintains a constant level of hydration at all times. If you want to avoid getting erroneous readings, you should try to weigh yourself at the same time every day, at a point in the day when you are certain that you will be adequately hydrated.

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