BMI Calculator — Body Mass Index

Calculate your BMI quickly using metric (kg & cm) or imperial (lb & in) units. This tool shows BMI value, category, and a healthy weight range for your height.

Age (optional)

Sex (optional) Prefer not to say Female Male Other

Units

Weight (kg)

Height (cm)

Weight (lb)

Height (ft) Height (in)

Note: BMI is a screening tool and does not distinguish between muscle and fat. For children & teens, use pediatric growth charts. For personalized medical advice, consult a healthcare professional.

Your Result

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Enter your details and click Calculate BMI.

BMI Categories (Adults)

• Underweight: < 18.5
• Normal weight: 18.5 – 24.9
• Overweight: 25.0 – 29.9
• Obesity: ≥ 30.0

These ranges follow common WHO definitions for adults. For children, use age- and sex-specific percentiles.

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Built for accuracy and ease-of-use. Metric formula: BMI = weight (kg) / (height (m))². Imperial formula: BMI = 703 × weight (lb) / (height (in))².

How it works

Enter weight and height in your preferred units and click Calculate BMI. The tool validates inputs and shows a BMI value rounded to one decimal place, the corresponding adult category, an interpretation message, and a healthy weight range for your height.