If you don’t know How to calculate BMI don’t worry, we will explain everything related BMI and tell you how to calculate body mass index in every units. This post is little bit lengthy because I tried to cover almost all topics related to BMI.
In this post you will learn about BMI Calculation, BMI Formula and everything related to BMI and what to do if BMI is low or high.
What is BMI?
Before calculating BMI let us know a little bit about BMI.
Body Mass Index(BMI) or Quetelet index is a value used to check your weight category.BMI is calculated based on a person’s weight and height.
BMI is a noninvasive and easiest way to calculate a person’s body fat. Adolphe Quetelet devised Quetelet Index and it was later renamed as Body Mass Index by Ancel Keys.
BMI is calculated by dividing weight in kilograms by square of height in metres.Using BMI value we can determine weather a person is underweight, normal weight, overweight or obese.
Body mass index gives you a estimate value of body fat with the help of BMI Formula or BMI equation.Though BMI is a very popular method of finding body fat it doesn’t work correctly for athletes, or peoples with muscular bodies.
If your BMI value is high your body fat level is high and if you have low BMI then your body fat level is low.
Before checking your BMI just be clear with these things. BMI is often considered as measurement of body fat but it’s actually a surrogate measure of body fat because it calculates excess weight not excess fat.
To make it more clear for you I will explain with an example. An athlete with good muscles will definitely have high BMI and falls in obese category. But actually he has a healthy weight. The BMI shows high BMI because it is calculated with Body Mass not Fat mass. So BMI is not suitable for few cases like athletes, pregnant women. Even If you don’t belongs to these cases it is good to measure your body fat with waist circumference, BMR Calculators.
Importance of BMI
Here are the few significance of Body Mass Index
- BMI indicates body fat and it is one of the popular and noninvasive method to find body fat.
- BMI helps us to determine health risk of a person and helps to know more about a person’s weight.
- It helps to relate the health of people with same age.
- It is noninvasive diagnostic tool for determining body fat.It gives approximate value of body fat.
- BMI has several categories which gives detailed idea about body fat.
- BMI is one of the important health parameter.
To calculate BMI we should know the height and weight.BMI is calculated using BMI formula.After BMI is calculated, the obtained BMI value is compared with BMI chart.It tells the health risk of that person.
How to Calculate BMI
There are two ways of calculating BMI. First way is to calculate BMI manually and the second way is calculating BMI with our online BMI Calculator. We have explained both ways of calculating Body Mass Index below.BMI for adults is same as normal method.
How to Calculate BMI Manually with BMI Formula or BMI equation
To manually calculate BMI we need our height and weight. After getting your height and weight substitute it in the deserved formula. Calculate the BMI and compare it to the BMI Chart to know your weight category.
BMI Formula or BMI Equation
BMI formula or equation help us to calculate BMI. There are two types of BMI Formula. The first is Metric BMI Formula which helps to calculate BMI in kg and feet. The second one is imperial BMI Formula which helps to calculate BMI in pounds.
BMI Formula Metric – How to Calculate BMI in kg
To calculate BMI in Kg use Metric BMI formula. Metric BMI Formula is
BMI = Weight (kg) / Height2 (m2)
Substitute the value of weight and height in the above formula. After calculating compare the value with BMI Chart or BMI Table.
BMI Formula Imperial – How to Calculate BMI in Pounds
To calculate BMI equation in Pounds use Imperial BMI Formula. The Imperial BMI formula is
BMI = Weight (lbs) * 703/ Height2 (inches2)
Substitute the value and calculate your BMI.
Steps to Calculate BMI?
Below are the steps to calculate BMI
- Note down the height of the person in meters.
- Note down the weight of the person in kilograms.
- Square the value of height and note it down.
- Divide weight in kilograms by the value obtained in previous steps
- Now you have successfully calculated BMI
- Compare the BMI value with the below BMI chart to know the health condition.
Using BMI Charts we can check in which category our BMI falls.If your BMI is under 18.5 you’re underweight.If your BMI falls between 18.5-25 you’re normal weight.If your BMI falls between 25-30 you’re overweight.If your BMI is above 30 you’re obese.
|Normal Weight||18.5 - 24.9|
|Overweight||25 - 29.9|
|Obese||30 - 35|
|Severely Obese||BMI > 35|
BMI Chart for Men
BMI Chart for men is same as normal chart. The Normal BMI for men is 18.5 to 24.9.If BMI of men is below 18.5 they are considered as underweight. Check the below image to know which Weight category you belongs to.
BMI Chart for Women
BMI Chart for women is probably same as men. In some cases the normal BMI range for women is considered from 19 to 24.9 not 18.5 to 24.9.Check below image for BMI Chart of women.
BMI For Childrens and Teens
BMI for childrens and teens (2-19)yrs is little bit different.We need to check BMI Percentile to calculate BMI.Check this post to know how to calculate BMI for children.
Calculate BMI For Women
BMI for women is same as women but there are different opinions exists while ranging underweight category.The most common range for underweight category is 19.
Limitations of BMI
- It only tells obesity but not the amount of composition of body like muscles, bone, fat etc.
- BMI of taller people are mislead due to scaling in calculating BMI.
- It doesn’t differentiate muscle mass and fat mass.
- There are some variations in definition of categories.
Alternatives of BMI
- BMI Prime: BMI Prime is defined by slightly modifying BMI.It is a ratio of BMI value by upper limit optimal BMI.
- Waist Circumference: It is a good tool for fat indication.
- Surface-based body shape index: It is calculated using body surface area, vertical trunk circumference, waist circumference and height.
How to Reduce BMI?
If your BMI is above ideal level you should try to reduce it.
- First Consult to a doctor regarding your BMI.Doctor will give you a better tips than anyone else.
- Follow healthy diet.
- Avoid sugars as much as possible.
- Do exercises regularly.
- Consult a doctor.