BMI Calculator
Calculate your Body Mass Index from weight and height.
What Is BMI and How Is It Calculated?
BMI stands for Body Mass Index, a simple metric derived from your height and weight. The formula divides weight in kilograms by the square of height in meters. BMI provides a quick screening tool to categorize weight status: underweight (below 18.5), normal weight (18.5–24.9), overweight (25–29.9), and obese (30 and above).
How Do I Use This BMI Calculator?
Enter your height and weight in either metric or imperial units. The calculator instantly computes your BMI and shows which category it falls into. You can switch between kilograms/centimeters and pounds/feet-inches at any time. Results update as you type.
Is BMI a Reliable Health Indicator?
BMI is a useful starting point but has limitations. It does not distinguish between muscle mass and fat, so athletes may show a high BMI despite being fit. It also does not account for body fat distribution, age, or gender differences. Always consult a healthcare professional for a comprehensive health assessment.
Why Check Your BMI Online?
Quickly checking your BMI gives you a general sense of your weight status relative to height. It is useful before doctor visits, when setting fitness goals, or when tracking progress over time. This calculator is free, instant, and runs entirely in your browser — no health data is stored or shared.
What BMI Range Is Considered Healthy?
The World Health Organization classifies BMI as follows: below 18.5 is underweight, 18.5 to 24.9 is normal weight, 25.0 to 29.9 is overweight, and 30.0 and above is obese. These ranges apply to adults aged 20 and over. Children and teens use age- and sex-specific percentiles instead of fixed ranges. A BMI in the normal range is associated with lower risk of chronic diseases, though BMI is just one of many health indicators.