How to Calculate BMI for Men, Women & Children (With Charts)

Body Mass Index (BMI) is a widely used measurement that helps assess whether an individual has a 
healthy body weight for a specific height. Understanding how to calculate BMI is essential as it can 
provide insights into overall health and the risk of weight-related conditions. In this article, we’ll 
explain how to calculate BMI for men, women, and children, and provide helpful charts for quick 
reference. 

What is BMI? 
BMI is a calculation that yields a number used to categorize individuals based on their body weight 
relative to their height. While it is not a perfect measurement of body fat, it serves as a useful 
screening tool to identify potential weight issues that may lead to health problems. 

The BMI Formula 
The formula for calculating BMI is straightforward: 
[ \text{BMI} = \frac{\text{weight (kg)}}{\text{height (m)}^2} ] 
For those who prefer using pounds and inches, the formula can be expressed as: 
[ \text{BMI} = \frac{\text{weight (lbs)} \times 703}{\text{height (inches)}^2} ] 
How to Calculate BMI for Men and Women 

Step-by-Step Calculation 
1. Measure Height and Weight 
• Use a scale to measure your weight in kilograms (kg) or pounds (lbs). 
• Measure your height in meters (m) or inches (in). 
2. Use the Formula 
• Plug your measurements into the appropriate formula (either metric or imperial). 
3. Calculate 
• Perform the calculation to determine your BMI. 
Example Calculation for Adults 
• Weight: 70 kg (154 lbs) 
• Height: 1.75 m (68.9 inches) 
Using the metric formula: [ \text{BMI} = \frac{70}{1.75^2} = \frac{70}{3.0625} \approx 22.86 ] 

Using the imperial formula: [ \text{BMI} = \frac{154 \times 703}{68.9^2} = \frac{108962}{4743.81} 
\approx 22.98 ] 

In both cases, the BMI rounds to approximately 22.9, indicating a normal weight. 

BMI Categories for Adults 
Category 
BMI Range 
Underweight 
Less than 18.5 
Normal weight 
18.5 - 24.9 
Overweight 
25.0 - 29.9 
Obesity (Class 1) 
30.0 - 34.9 
Obesity (Class 2) 
35.0 - 39.9 
Obesity (Class 3) 
40.0 and above

How to Calculate BMI for Children 
Calculating BMI for children is slightly different due to variations in growth rates and body 
composition. It is usually age- and gender-specific. Use the same formula, but interpret the BMI 
number using growth charts specific to children's BMI. 

Step-by-Step Calculation for Children 
1. Measure Height and Weight: As with adults, measure weight and height. 
2. Calculate BMI using the formula: Plug in the numbers. 
3. Use Growth Charts: After calculating BMI, plot the result on a child BMI-for-age growth 
chart. This will help you see how the child's BMI compares with peers. 

Acceptable BMI Ranges for Children
BMI percentiles for children are categorized much like adult ranges but differ based on age . 
Generally, a healthy BMI falls within the 5th to 85th percentile. 

Percentile 
Category 
Less than 5th 
Underweight 
5th - 85th 
Healthy Weight 
85th - 95th 
Overweight 
Greater than 95th 
Obese 

Tools to Simplify BMI Calculation
While manually calculating BMI can be useful, utilizing online calculators can make the process even 
faster. Additionally, some fitness apps and health monitoring tools include BMI calculators. A Term 
Insurance Calculator can also be handy, as many users look for overall wellness metrics, including 
BMI, when applying for term insurance. 

Conclusion 
Knowing how to calculate BMI is an integral part of understanding your health. Whether you are 
calculating BMI for yourself, your partner, or your child, it is important to consult with healthcare 
providers to interpret these figures correctly, especially when making fitness or dietary decisions. 
Use the provided charts and formulas to guide you, and don't hesitate to seek professional advice if 
you have concerns regarding your BMI measurements. Remember, BMI is just one indicator of 
health; it’s essential to consider additional factors such as diet, physical activity, and genetics.