###### Webzel
calculate your BMI and weight status based on your age, height and weight.

# How to Use a Calculator for Calculating BMI

BMI, or body mass index, is a measure of body fat based on your height and weight. It can help you determine whether you are underweight, normal weight, overweight, or obese. Knowing your BMI can also help you assess your health risks and plan your weight management goals.

There are many online tools and apps that can help you calculate your BMI easily. However, if you want to use a calculator for calculating BMI, you need to know the formula and the units of measurement. In this article, we will explain how to use a calculator for calculating BMI in both standard and metric units.

## What is the Formula for Calculating BMI?

The formula for calculating BMI is simple: divide your weight by your height squared. However, depending on the units of measurement you use, you may need to apply some conversions or adjustments.

### Calculating BMI in Metric Units

If you use metric units, such as kilograms and meters, the formula for calculating BMI is:

`BMI = weight in kg / height in m2`

For example, if your weight is 73 kg and your height is 1.70 m, your BMI is:

`BMI = 73 / 1.702` `BMI = 73 / 2.89` `BMI = 25.26 kg/m2`

### Calculating BMI in Standard Units

If you use standard units, such as pounds and inches, the formula for calculating BMI is slightly different:

`BMI = weight in lb / height in in2 x 703`

The factor of 703 is used to convert the units from lb/in2 to kg/m2. For example, if your weight is 160 lb and your height is 68 in, your BMI is:

`BMI = 160 / 682 x 703` `BMI = 160 / 4624 x 703` `BMI = 24.53 kg/m2`

## What are the BMI Categories and Ranges?

Once you have calculated your BMI, you can compare it with the standard BMI categories and ranges to see where you stand. The World Health Organization (WHO) recommends the following BMI categories and ranges for adults1:

ClassificationBMI range – kg/m2
Severe Thinness< 16
Moderate Thinness16 – 17
Mild Thinness17 – 18.5
Normal18.5 – 25
Overweight25 – 30
Obese Class I30 – 35
Obese Class II35 – 40
Obese Class III> 40

The BMI categories and ranges may vary slightly depending on factors such as age, gender, ethnicity, and health conditions. For children and teens, the Centers for Disease Control and Prevention (CDC) recommends using BMI-for-age percentiles to assess growth and development2. You can use online tools or charts to find the appropriate BMI percentile for your child or teen.

## What are the Benefits and Limitations of Calculating BMI?

Calculating BMI can be a useful way to estimate your body fat and health risks. It can help you monitor your weight status and set realistic goals for weight loss or gain. It can also help you prevent or manage chronic diseases such as diabetes, heart disease, high blood pressure, and some cancers that are associated with being overweight or obese3.

However, calculating BMI also has some limitations. It does not take into account your body composition, such as muscle mass, bone density, or fat distribution. It may overestimate or underestimate your body fat if you are very muscular, very tall or short, pregnant, or have a medical condition that affects your weight or height. It may also not reflect the health risks of different types of fat, such as visceral fat or subcutaneous fat4. Therefore, BMI should not be used as the sole indicator of your health status. You should also consider other factors such as your waist circumference, blood pressure, blood sugar, cholesterol levels, and physical activity levels.

## Conclusion

BMI is a simple and widely used measure of body fat based on your height and weight. You can use a calculator for calculating BMI by following the formula and the units of measurement. You can then compare your BMI with the standard categories and ranges to see where you stand. However, you should also be aware of the benefits and limitations of calculating BMI and use other methods to assess your health risks and goals.

## BMI Calculator FAQs

BMI stands for body mass index, a measure of whether you’re a healthy weight for your height. It is widely used as a general indicator of whether a person has a healthy body weight for their height. However, BMI may underestimate or overestimate the health risks for some people, such as those who are very muscular, pregnant, or of Asian origin.
To calculate BMI, you need to know your weight in kilograms and your height in meters. Then, you can use this formula: BMI = weight / height^2. For example, if your weight is 75 kilograms and your height is 1.8 meters, then your BMI is 75 / 1.8^2 = 23.15.
The World Health Organization (WHO) has defined the following BMI categories for adults: – Underweight: BMI less than 18.5 – Normal weight: BMI between 18.5 and 24.9 – Overweight: BMI between 25 and 29.9 – Obese: BMI 30 or more
Being overweight or obese increases the risk of a number of serious diseases and health conditions, such as: – Type 2 diabetes – Heart disease – Stroke – High blood pressure – High cholesterol – Certain cancers – Osteoarthritis – Sleep apnea – Gallstones
Having a healthy BMI can help you: – Feel more energetic and confident – Reduce the risk of developing chronic diseases – Improve your mood and mental health – Enhance your physical performance and fitness – Maintain a healthy body image and self-esteem