BMI calculator

Calculate your Body Mass Index instantly. Mix and match metric and imperial units — no need to convert first.

kg, lbs or stone for weight
cm, m or ft/in for height
Instant BMI category result
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Weight

Height

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About BMI

Body Mass Index was developed by Belgian mathematician Adolphe Quetelet in the 1830s and remains the most widely used screening tool for weight categories. While BMI is a useful indicator, it doesn't account for muscle mass or bone density — always consult a healthcare professional for a full assessment.

What is a healthy BMI range?

For most adults, a BMI between 18.5 and 24.9 is considered healthy. Below 18.5 is underweight; 25–29.9 is overweight; 30 and above is obese.

Is BMI accurate for everyone?

BMI has limitations. Athletes with high muscle mass may show a high BMI despite being healthy. Different ethnic groups may have different healthy BMI thresholds.