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BMI Calculator (Body Mass Index)

Calculate your BMI in metric (kg/cm) or imperial (lbs/ft) units. Includes BMI category, healthy weight range, and limitations of BMI as a health metric.

✔ WHO BMI Scale🌍 Metric & Imperial

⚖️ BMI Calculator (Body Mass Index)

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Imperial (lbs, ft)
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Your BMI
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Your BMI
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Healthy Range (BMI 18.5–24.9)
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ℹ️ BMI is a screening tool, not a diagnostic measure. It does not account for muscle mass, bone density, age, or fat distribution. Consult a healthcare professional for health assessment.

What Is BMI and How Is It Calculated?

Body Mass Index (BMI) is a simple numerical measure of body weight relative to height. It was developed by Belgian mathematician Adolphe Quetelet in the 1830s and adopted by the WHO as a population-level screening tool. BMI does not directly measure body fat — it is a proxy that works reasonably well at a population level but has well-documented limitations at the individual level.

📐 BMI Formula

BMI = Weight (kg) ÷ Height² (m²)
ImperialBMI = 703 × Weight (lbs) ÷ Height² (inches)
<18.5Underweight
18.5–24.9Normal weight
25.0–29.9Overweight
≥30Obese

Limitations of BMI

BMI overestimates adiposity in muscular individuals (athletes often register as "overweight" despite low body fat) and underestimates it in older adults who have lost muscle mass. It also does not account for fat distribution — abdominal (visceral) fat carries higher health risks than peripheral fat. Ethnicity also affects optimal BMI ranges; Asian populations tend to have higher cardiometabolic risk at lower BMI values.

Frequently Asked Questions

BMI is a useful population screening tool but a poor individual health diagnostic. Studies show it correctly identifies weight status in about 50% of individuals. A better picture of health comes from multiple metrics: BMI, waist circumference, waist-to-height ratio, blood pressure, blood glucose, and cholesterol levels. Discuss your overall health profile with your doctor.
The WHO defines the healthy BMI range for adults as 18.5 to 24.9. However, many health authorities note that for people of Asian descent, a lower threshold of 23.0 may be more appropriate, as cardiometabolic risk increases at lower BMI values in these populations.
⚠️ Disclaimer Estimates for informational purposes only. Not legal or financial advice. Consult a qualified professional.