BMI Calculator

Body Mass Index (BMI) is a numerical value calculated from a person's weight and height. It provides a simple way to classify whether a person has a healthy body weight for their height. BMI is widely used as a screening tool to identify potential weight problems in adults.

While BMI is not a direct measure of body fat, it correlates reasonably well with more direct measures of body fat for most people and is an inexpensive and easy-to-perform method of screening for weight categories that may lead to health problems.

BMI is calculated using the formula:

BMI = weight(kg) / [height(m)]²

For example, if you weigh 70 kg and are 1.75 meters tall, your BMI would be calculated as:

BMI = 70 / (1.75)² = 70 / 3.0625 = 22.86

In the imperial system (pounds and inches), the formula is:

BMI = [weight(lb) / height(in)²] × 703

BMI values are categorized as follows:

• Underweight: BMI less than 18.5 • Normal weight: BMI 18.5 to 24.9 • Overweight: BMI 25 to 29.9 • Obesity (Class 1): BMI 30 to 34.9 • Obesity (Class 2): BMI 35 to 39.9 • Extreme Obesity (Class 3): BMI 40 or higher

Being in the overweight or obese categories increases your risk for various health conditions including heart disease, high blood pressure, type 2 diabetes, gallstones, breathing problems, and certain cancers. Being underweight can also pose health risks such as malnutrition, decreased immune function, and osteoporosis.

While BMI is a useful tool for most people, it does have limitations:

1. It doesn't distinguish between fat, muscle, and bone mass. Athletes with high muscle mass may have a high BMI but low body fat.

2. It doesn't account for where fat is stored in the body. Abdominal fat (around the waist) poses more health risks than fat stored in other areas.

3. It may not be as accurate for elderly individuals who have lost muscle mass, pregnant women, or certain ethnic groups.

4. It doesn't account for other factors that influence health, such as diet, physical activity, genetics, and other medical conditions.