BMI Calculator
Calculate your Body Mass Index (BMI) instantly. Enter your height and weight to find out if you are in a healthy weight range.
How to Use This BMI Calculator
- Select your preferred unit system: Metric (kg/cm) or Imperial (lbs/ft+in).
- Enter your weight in the weight field.
- Enter your height. For imperial units, enter both feet and inches.
- Your BMI is calculated in real time and displayed with a color-coded category.
- Check the healthy weight range card to see the recommended weight for your height.
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Frequently Asked Questions
What is BMI?
BMI (Body Mass Index) is a numerical value calculated from your weight and height. It is used as a screening tool to categorize individuals into weight status categories: underweight, normal weight, overweight, and obese. The formula is weight in kilograms divided by height in meters squared.
What is a healthy BMI range?
A healthy BMI is generally considered to be between 18.5 and 24.9. A BMI below 18.5 is classified as underweight, 25 to 29.9 as overweight, and 30 or above as obese. These ranges apply to most adults but may vary based on age, sex, and ethnicity.
What are the limitations of BMI?
BMI does not distinguish between muscle mass and fat mass, so muscular individuals may have a high BMI without excess body fat. It also does not account for fat distribution, bone density, age, or sex differences. BMI is a screening tool and should not be used as the sole indicator of health.
How is BMI calculated?
BMI is calculated by dividing your weight in kilograms by the square of your height in meters: BMI = weight (kg) / height (m)². For imperial units, the formula is BMI = (weight in pounds x 703) / (height in inches)².
Understanding Body Mass Index
Body Mass Index (BMI) is one of the most widely used metrics in public health and clinical medicine for assessing weight status at the population level. Developed by Belgian mathematician Adolphe Quetelet in the 1830s, BMI provides a simple ratio of weight to height that correlates with body fat percentage for most adults. Healthcare providers use BMI as an initial screening tool during routine checkups to identify potential weight-related health risks, including cardiovascular disease, type 2 diabetes, and certain cancers.
However, BMI has well-documented limitations. It cannot differentiate between lean muscle mass and body fat, meaning athletes and highly active individuals may be classified as overweight despite having low body fat percentages. Additionally, BMI does not indicate where fat is stored in the body. Visceral fat around the abdomen carries greater health risks than subcutaneous fat elsewhere. For a more comprehensive assessment, clinicians often combine BMI with waist circumference measurements, body composition analysis, and other health markers such as blood pressure, cholesterol, and blood glucose levels. BMI remains a useful starting point, but it should always be interpreted alongside other indicators of overall health.