BMI Calculator
Calculate your Body Mass Index (BMI) to check if your weight is in a healthy range. Supports both metric and imperial units.
BMI Categories
| Category | BMI Range |
|---|---|
| Underweight | Less than 18.5 |
| Normal weight | 18.5 – 24.9 |
| Overweight | 25.0 – 29.9 |
| Obese | 30.0 and above |
How to Use the BMI Calculator
This calculator makes it easy to determine your Body Mass Index in just a few steps:
- Choose your unit system — Select the Metric tab (kg/cm) or Imperial tab (lbs/ft) depending on your preference.
- Enter your weight and height — Type your weight and height into the respective fields. For imperial, enter feet and inches separately.
- Click "Calculate BMI" — Your BMI value, category, and healthy weight range will be displayed instantly.
- Review the BMI categories table — Compare your result against the standard WHO BMI classification ranges.
About BMI (Body Mass Index)
Body Mass Index (BMI) is a widely used screening tool that estimates body fat based on a person's weight relative to their height. Developed by Belgian mathematician Adolphe Quetelet in the 1830s, BMI is calculated using the formula: BMI = weight (kg) / height (m)².
BMI is commonly used by healthcare providers to identify potential weight-related health risks. While it does not directly measure body fat percentage, it provides a quick and easy way to categorize individuals into weight status groups. The World Health Organization (WHO) recognizes four primary BMI categories: underweight, normal weight, overweight, and obese.
It is important to note that BMI has limitations. It does not distinguish between muscle mass and fat mass, meaning that muscular individuals may have a high BMI without excess body fat. Age, gender, ethnicity, and body composition can all influence how BMI should be interpreted. For a complete health assessment, consult with a medical professional.
Frequently Asked Questions
BMI (Body Mass Index) is a numerical value calculated from your weight and height. The formula is BMI = weight (kg) / height (m)². For imperial units, the formula is BMI = (weight in lbs × 703) / (height in inches)². It is used as a screening tool to identify potential weight problems in adults.
The standard BMI categories for adults are: Underweight (BMI below 18.5), Normal weight (BMI 18.5 to 24.9), Overweight (BMI 25 to 29.9), and Obese (BMI 30 and above). These categories apply to both men and women aged 20 and older.
BMI is a useful general indicator but has limitations. It may overestimate body fat in athletes and muscular individuals, and underestimate it in older adults who have lost muscle mass. It also does not account for differences in body composition related to age, gender, or ethnicity. Always consult a healthcare professional for personalized advice.
A healthy BMI is generally considered to be between 18.5 and 24.9. Within this range, you are less likely to develop weight-related health issues such as heart disease, type 2 diabetes, and certain cancers. However, BMI is just one factor in overall health assessment.