BMI Calculator to Check Your Body Mass Index

What is BMI Calculator

• Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women using the BMI Calculator.
• BMI is the main indicator used to measure the index of obesity.

 

Steps to Use BMI Calculator

1. Enter Your Age & Select Your Gender.
2. Put your weight and height using standard or metric measures.
3. Compute BMI and your BMI will appear below.
4. To calculate BMI, multiply weight in pounds by 703, divide by height in inches, and then divide again by height in inches or you can divide weight in kilograms by height in meters squared.

 

Healthy BMI Range

Here are Healthy BMI Range Tables are given to calculate Body Mass Index (BMI) using BMI Calculator.

BMI (Kg/m²)	Class
Less than 18.5	Underweight
Between 18.5 - 25.0	Normal Weight
Between 25.0 - 30.0	Over Weight
Between 30.0 - 35.0	Class 1 Obesity
Between 35.0 - 40.0	Class 2 Obesity
40.0 or over	Morbid Obesity or Class 3 Obesity

 

 

BMI Calculator Chart Ranges

 

Underweight: BMI less than 18.5 kg/m²

• A BMI of less than <18.5 indicates that you are underweight, so you may need to put on some weight.
• You are advised to ask your doctor or a dietitian for advice in BMI Calculator.

 

Normal Weight: BMI ranges between 18.5–24.9 kg/m²

• A BMI range of 18.5-24.9 indicates that you have a healthy weight according to your height.
• You lower your risk of developing serious health problems by maintaining a healthy weight in the BMI Calculator.

 

Overweight: BMI range between 25–29.9 kg/m²

• A BMI range of 25-29.9 indicates that you are slightly overweight.
• You may be advised to lose some weight for health reasons.
• You are advised to talk to your doctor or a dietitian for advice using BMI Calculator.

 

Obesity Definition BMI over 30 kg/m²

• A BMI of over 30 indicates that you are heavily overweight.
• Your health may be at risk if you do not lose weight.
• You are advised to talk to your doctor or a dietitian for nutrition advice in BMI Calculator.

 

Abdominal Obesity

• Abdominal obesity is defined as a waist circumference of more than 102 cm (40 inches) in men and more than 88 cm (35 inches) in women according to International Diabetes Federation for Asian Population (IDF).

 

BMI Calculator table for adults

This is the World Health Organization's (WHO) recommended body weight based on BMI values for adults using BMI Calculator. It is used for both men and women, aged 20 or older.

Category	BMI range - kg/m²
Severe Thinness	< 16
Moderate Thinness	16 - 17
Mild Thinness	17 - 18.5
Normal	18.5 - 25
Overweight	25 - 30
Obese Class I	30 - 35
Obese Class II	35 - 40
Obese Class III	> 40

 

BMI table for children age 2-20

The Centers for Disease Control and Prevention (CDC) recommends BMI categorization for children and teens between age of 2 and 20 using BMI Calculator.

Category	BMI range - kg/m²
Underweight	<5%
Healthy weight	5% - 85%
At the risk of overweight	85% - 95%
Overweight	>95%

 

Ponderal Index

• The Ponderal Index (PI) is similar to BMI in that it measures the leanness or corpulence of a person based on height and weight.
• The main difference between the PI and BMI is the cubing rather than squaring of the height in the formula in the BMI Calculator (provided below).
• While BMI can be a useful tool when considering large populations, it is not reliable for determining leanness or corpulence in individuals.
• Although the PI suffers from similar considerations, the PI is more reliable for use with very tall or short individuals, while BMI tends to record uncharacteristically high or low body fat levels for those on the extreme ends of the height and weight spectrum.
• Below is the equation for computing the PI of an individual using USC, again using a 5'10", 160-pound individual as an example:

 

BMI Calculator For Children

• Your GP or health visitor can advise on where your child sits on the ‘centile charts’ used to estimate healthy weights for children using BMI Calculator.

 

BMI Calculator For Older people (over 65, possibly over 60)

• Because muscle mass tends to drop and body fat tends to rise in older people, BMI may not be an accurate reflector of body fat if you're over 60 using the BMI Calculator.

 

BMI Calculator For Pregnant women

• Usual BMI estimates do not apply if you’re pregnant using the BMI Calculator.

 

BMI Calculator If you are very muscular

• BMI assumes you have an average amount of body fat, including ‘intra-abdominal fat’ – fat deep inside your stomach cavity rather than under your skin.
• Intra-abdominal fat is much more closely linked to risks of type 2 diabetes and heart disease than fat under the skin due to less nutrition.
• If you are very muscular, your level of body fat may be lower than predicted by your BMI using the BMI Calculator.
• However, this only applies to people who do high levels of exercise – much more than average.

 

BMI Calculator If you are of Asian origin

• People of Asian origin are prone to accumulating intra-abdominal fat (fat deep inside your stomach cavity rather than under your skin) at a lower BMI than people of Caucasian origin.
• People with this pattern of weight gain are described as ‘apples’ rather than ‘pears’ from their body outline.
• This means their health risks start to rise at a lower BMI because intra-abdominal fat is directly linked to the development of heart disease and type 2 diabetes.
• The World Health Organisation has looked at the evidence and because of the variability between different Asian populations, it hasn't officially changed the cut-off points using BMI Calculator.
• However, it does recommend that for public health purposes, some Asian groups should be considered overweight if their BMI is 22-25, and obese with a BMI of 26-31.

 

What is BMI (Body Mass Index) in Medical Terminology

• BMI is a measurement of a person's leanness or corpulence based on height and weight and is intended to quantify tissue mass.
• It is widely used as a general indicator of whether a person has a healthy body weight for their height using the BMI Calculator.
• Specifically, the value obtained from the calculation of BMI is used to categorize whether a person is underweight, normal weight, overweight, or obese depending on what range the value falls between.
• These ranges of BMI vary based on factors such as region and age and are sometimes further divided into subcategories such as severely underweight or very severely obese.
• Being overweight or underweight can have significant health effects, so while BMI is an imperfect measure of healthy body weight, it is a useful indicator of whether any additional testing or action is required.
• Refer to the table below to see the different categories based on BMI that are used by the BMI Calculator.

 

Alternative estimates of weight-related health risks

If you feel BMI may not accurately reflect whether you are overweight or obese, measuring your abdominal circumference, waist-hip, or waist-height ratio may give you a more realistic estimate in the BMI Calculator.

 

Why waist size also matters

• Measuring your waist is a good way to check you're not carrying too much fat around your stomach, which can raise your risk of heart disease, type 2 diabetes, and stroke.
• You can have a Healthy BMI Range and still have excess tummy fat, meaning you're still at risk of developing these conditions using the BMI Calculator.

 

To measure your waist:

1. Find the bottom of your ribs and the top of your hips using the BMI Calculator.
2. Wrap a tape measure around your waist midway between these points.
3. Breathe out naturally before taking the measurement.

 

Regardless of your height or BMI, you should try to lose weight if your waist is:

• 94cm (37ins) or more for men
• 80cm (31.5ins) or more for women

 

You're at very high risk and should contact a GP if your waist is:

• 102cm (40ins) or more for men
• 88cm (34ins) or more for women

 

Waist circumference

You measure your waist circumference halfway between the bottom of your ribcage and the top of your hip bones, with the tape measure parallel to the floor.

You must be breathing out when you measure in BMI Calculator.

 

Male

• Increased health risk - ≥94cm
• High health risk - ≥102cm

 

Female

• Increased health risk - ≥80cm
• High health risk - ≥88cm

 

Waist to hip ratio

To check your waist to hip ratio, measure your waist circumference (as above), and your hip size at the widest part of your hips. Divide your abdominal circumference by your hip measurement to give a ratio in BMI Calculator.

• In women, a waist to hip ratio greater than 0.85 is associated with greater than average risk.
• In men, a waist to hip ratio greater than 1.00 is associated with greater than average risk.

 

Waist to height ratio

A recent study comparing BMI, waist circumference, waist to hip ratio and waist to height ratio found that the most accurate way of predicting your whole-body fat level was waist-height ratio.

Measure your waist circumference as above and simply divide it by your height – fairly obviously both measurements should either be in imperial (inches) or metric (cm).

Whole body obesity is defined by a waist-height ratio of:

• 0.53 or more for men
• 0.54 or more for women

Abdominal obesity was defined by a waist-height ratio of 0.59 or more in the BMI Calculator.

 

How to calculate BMI

• If you want to calculate your BMI, you have to find out your weight and height first in BMI Calculator.
• Once you know these values, you can arrive at the result by following the two steps mentioned below in BMI Calculator:

1. Multiply your height by itself (height X height).
2. Divide your weight by the answer you get in the first step.

 

The equations for calculating the BMI in BMI Calculator are as follows:

 

1. International System of Units (SI)

   BMI = weight (kg) ÷ (height (m))²

   Example:

   For a 177 cm (1.77 m) individual weighing 75 kg,

   BMI = 75 / (1.77 * 1.77) = 75/ 3.13 = 23.96

2. Imperial System

   BMI = weight (lbs) ÷ (height (inches))² × 703

   Example:

   For a 160-pound, 5’8” (68”) individual weighing 75 kg,

   BMI = (160/ 68*68) * 703 = (160/4624) * 703 = 24.3

 

Limitations of an Online BMI Calculator

• Despite its popularity, BMI figures do have certain drawbacks when it comes to predicting future health issues.
• Your BMI only uses your height and weight and does not consider your body composition.
• So, the distribution of your muscle and bone mass might increase your BMI even if you’re very healthy and not likely to suffer from weight-related health issues in the near future.
• Let’s take a closer look at the limitations of using BMI for various age groups using the BMI Calculator:

 

Adults

• BMI is not considered accurate since it only measures excess body weight instead of excess body fat.
• Use BMI Calculator For all your doubts.
• So, it’s a good idea for adults to use BMI along with other measures to understand their future health risks.

 

The drawbacks of using the BMI Calculator for adults include:

• Older adults will likely have more fat than younger individuals who have the same BMI.
• Women are more likely to have more body fat than men who have an equivalent BMI.
• Athletes and muscular people will probably have a higher BMI than others since they have large muscle mass.

 

Young Adults and Children

• BMI cannot take into account a child’s growth rate and maturity.
• Typically, BMI can be used to identify obese children, but not overweight children as a slightly higher BMI could be caused by increased fat-free mass.
• Use BMI Calculator to track everything.
• Despite the slight discrepancies, it’s possible to use BMI to accurately indicate the body fat of around 90% of the population.

 

What are the health risks related to being overweight?

Excess weight brings with it countless health complications, some of which can be fatal. A higher BMI than average (over 25) is associated with increased risks for diseases like:

• Type 2 diabetes
• Heart conditions
• Higher levels of LDL cholesterol and lower count of HDL cholesterol in the blood, increase the chances of coronary artery diseases and heart attacks
• High triglycerides
• Stroke
• High blood pressure
• Gall bladder-related complications
• Insulin resistance
• Osteoarthritis or breakdown of joint cartilage leading to painful joints
• Sleep apnea or intermittent breathing obstruction during sleep
• Atherosclerosis or the building up of cholesterol deposits (plaques) in blood vessels (arteries)
• Skin health problems like skin tags, darkening of the skin
• Breathing trouble
• Hernia
• Varicose veins
• Cataract
• Gout
• Stress incontinence or urge to urinate frequently
• Certain types of cancer (breast, colon, endometrial, gall bladder, kidney, liver)
• Clinical depression and other mental health issues
• Polycystic ovarian disease in women leads to reduced fertility and other menstrual irregularities.

 

What are the risks of being underweight?

Having a BMI below 18.5 is also fraught with health risks, such as the ones listed below:

• Vitamin deficiencies
• Anemia (low red blood cell count and hence reduced capacity to carry oxygen)
• Diminished immunity or the ability to ward off infections
• Osteoporosis or brittle bones that break easily
• Malnutrition
• Developmental delays in children
• Hormonal imbalances
• Disruptions in women's menstrual cycle cause complications in conception
• Less nutrition in your body weight

 

Summary

BMI Calculator helps to prevent obesity and know your healthy weight index value to keep your body in shape. Check More Medical Health Related Calculator on Drlogy Calculator to get exact health solution.

 

Reference

• Body mass index by Wikipedia [1].
• Calculate Your Body Mass Index [2].