Calculate your Body Mass Index (BMI) instantly. Enter your height and weight to see your BMI value, category and ideal weight range.
Enter your height and weight to calculate your BMI.
Body Mass Index (BMI) is a simple, widely-used measurement that estimates whether a person has a healthy weight for their height. It was developed in the 1830s by Belgian mathematician Adolphe Quetelet and is used worldwide by health professionals, fitness experts and researchers.
The BMI formula is:
BMI = weight (kg) / height² (m)
For example, if you weigh 70 kg and are 1.75 m tall:
BMI = 70 / (1.75 × 1.75) = 70 / 3.0625 = 22.86
According to the World Health Organization, adults fall into these categories:
While BMI is useful for population-level assessments, it has limitations. It doesn't distinguish between muscle and fat mass, so athletes with high muscle mass may register as "overweight" despite being very fit. It also doesn't account for age, sex, ethnicity or body composition. Always consult a healthcare professional for a complete health assessment.
All calculations happen instantly in your browser. Your height and weight are never sent to any server and never stored. This tool is 100% private and works offline once loaded.
According to the WHO, a healthy BMI for adults is between 18.5 and 24.9. However, BMI is just one indicator of health — it doesn't account for muscle mass, bone density or body composition. Always consult a healthcare professional for a complete assessment.
This calculator uses adult BMI standards (WHO). For children and teens (ages 2-19), BMI is interpreted differently using age- and sex-specific percentiles. Please consult your pediatrician for accurate assessments of children's BMI.
BMI can be misleading for people with high muscle mass, since muscle weighs more than fat. Athletes and bodybuilders may register as 'overweight' or 'obese' on BMI while having very low body fat. For those individuals, body fat percentage measurements are more accurate.
The BMI value is the same — only the input units differ. Metric uses kilograms and meters (or centimeters), while imperial uses pounds and feet/inches. Our calculator automatically converts and gives you the same BMI result either way.
Not necessarily. BMI is a screening tool, not a diagnostic one. If your BMI is in the overweight or obese range, it's a good idea to talk to a doctor who can consider other factors like body composition, muscle mass, family history and overall health before recommending any weight change.
Yes! All calculations happen entirely in your browser. Your height and weight are never sent to any server, never stored, and never shared with anyone. Your privacy is fully protected.