BMI Calculator
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About BMI Calculator
Calculate Body Mass Index (BMI) from height and weight. Metric (kg/cm) or US (lb/in) units. Shows the WHO category (underweight / normal / overweight / obese).
BMI = weight (kg) ÷ height² (m²). It's a screening tool, not a diagnosis. The category boundaries (18.5 / 25 / 30) are population-level statistics that don't account for muscle mass, body composition, ethnicity, or age — a body-builder with 10% body fat can be BMI-overweight, an elderly person at 'normal' BMI can be at risk of sarcopenia.
For more nuanced body-composition assessment, look at waist-to-hip ratio, body fat percentage, or DXA scan. BMI is useful as a rough screen and a population-level metric; clinically it's one input alongside others.
Common questions
What's a healthy BMI?
Why is BMI considered flawed?
Like every tool on Buncha, this one runs entirely in your browser. There's no upload, no log, no record of what you've pasted or generated. Close the tab and the data is gone.