What is BMI Formula: Easy and Step-by-Step Calculation Guide

BMI Formula

Find out how to calculate your BMI online or manually. Calculating BMI is easy. You can use a BMI formula or insert the required values in one of the many free BMI calculators available online. To calculate your BMI scale, you will need to:

Get a weighing scale and measure your weight. Note it to the nearest pound value.-
Measure your height in feet and inches. Stand against a wall and mark your height, then use a measuring scale to check the height.

Once you know your correct height and weight, you can calculate your BMI scale manually by using a verified BMI formula.

International BMI formula:

BMI = Weight (Kilograms) / Height (metres)2

Imperial System BMI formula:

BMI = (Weight (lbs)/Height (Inches)2) *703

So, for a person who is 175cms (1.75m) and weighs 75 kgs. The BMI (as per the international BMI formula) = 75kg/(1.75m2) = 24.49kg/m2.

The body mass index calculator helps you better understand your health. A low or high BMI range can be a matter of concern as it may indicate health risks, especially with increasing age. Understanding your BMI can help you track your overall health and minimise and prevent several health risks. If your BMI results are above or under the ideal BMI scale, you should take preventive measures and get yourself checked at least every six months.

The BMI calculator will give your BMI scale based on your inputs. If the results are in the appropriate BMI scale, there is nothing to worry about. However, if you have a low or a high BMI, it is best to consult a doctor to help reduce the health risks associated and eventually work on your diet to get your weight in the healthy category.

For adults, ideally, a BMI between 18.5 and 24.9 is healthy. Less than 15 is considered severely underweight. Alternatively, a BMI scale of 15 to 18 is underweight. BMI scale of 25 to 30 is overweight, and a BMI value between 30 and 40 or above 40 is considered obese and severely
obese.

BMI Calculation

Find out how a BMI Calculator works and the formula it uses.

A BMI calculator or a body mass index calculator is an offline and online tool that correlates your body weight with your height to assess if your weight is right for your stature. Typically, the BMI calculator measures your body mass (fat in the body, including muscles and bones) with your weight and height.

The BMI tool takes your weight and divides the figure by the square of your height. The result helps you understand if your BMI corresponds to a healthy range according to the corresponding BMI range. For most adults, the BMI range is between 18.5 and 24.9. For children between 2 and 20 years, the BMI calculator also considers age and gender with height and weight.

For adults above 20 years, BMI is calculated using the standard weight measures. This implies there is no different BMI calculator for men or BMI calculator for women. Everyone can use the standard BMI calculator offline and online.

BMI calculator does not directly measure body fat as it does not account for age, sex, ethnicity, muscle mass, etc. However, the tool uses standard weight category status, which can provide a fair indication of potential health issues. When combined with other health parameters, the results from a BMI calculator can help assess your holistic health condition.

Here are some reasons why you should use an online body mass index calculator

An online BMI calculator can help you understand if your BMI value is within the healthy weight range or is deviated.-

- An online BMI calculator can help you understand if your BMI value is within the healthy weight range or is deviated.

- If the BMI calculator shows a deviated value, you can take measures to reduce the health risk.

- BMI helps your doctor or nutritionist prepare the right diet and exercise chart and eventually get your BMI values in the healthy range.

- BMI calculator tool is inexpensive, easy to use and gives quick results.

- BMI measures the level of obesity, which can help the doctor in identifying and mitigating associated health risks.

- BMI helps guide fitness and health goals.

Ideal BMI for adults

Learn how you can interpret BMI results for adult men and women.

The body mass index chart for adults (above 20 years of age) and children (between 2 and 20 years of age) is different.For adults over 20 years of age, the BMI chart is classified into the following weight status categories:

The BMI range remains the same for men and women. As per WHO, BMI values below 18.5 are underweight. If the body mass index of a person is between 18.5 and 29.5, then the person is healthy. However, deviations of body mass index below and above this range indicate health risks.
A body mass index between 25 and 29.9 indicates that one is overweight, and a body mass index beyond 30 is obesity. For clinical purposes, obesity can be divided into three categories:

• Class 1 BMI between 30 and 34.9
• Class 2:BMI between 35 and 39.9
• Class 3:BMI above 40
  
  

Ideal BMI for children

Learn how you can interpret BMI results for children.

Calculating BMI for children is as important as calculating body mass index for adults. By knowing the body mass index of your child, you can assess if your child is growing normally. Moreover, if the BMI values of the child are high or low, you can take preventive measures to avoid
any health issues that may arise in the future.

Calculating and reading BMI for children is different from adults. This is because the body fat in children changes as they grow and is influenced by their gender. The BMI calculator for children divides the child's weight (in kilograms) by the child's height (in metres squared) and further multiplies the total result by 703.

For children above two years and less than 20 years, the fat content changes with age. Some girls might have more body fat than boys of their age. Once you know the standard BMI of your child, the BMI value is compared to other children of the same age and gender. This is done with a distinct BMI chart that includes percentages and percentiles.

The BMI range according to percentages and percentiles, is:

Less than the 5th percentile: Underweight
Above the 5th but lower than the 85th percentile: Normal weight
Above 85th percentile but lower than the 95th percentile: Overweight
BMI more than or equal to the 95th percentile: Obesity

As per this BMI chart, if your child has a 25th BMI percentile, then they are in the normal weight range. Also, the child’s weight is higher than 25% of the children of the same age. The BMI percentile is assessed in correspondence to the gender of the child.