BMI Calculator
Calculate your Body Mass Index and find out which weight category you fall into.
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How to use this calculator
Divide your weight in kilograms by the square of your height in metres.
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Enter your weight in kilograms.
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Enter your height in centimetres.
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Your BMI and weight category appear instantly.
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The ideal weight range shows the healthy BMI span for your height.
Frequently asked questions
What is a healthy BMI?
The World Health Organization defines a healthy BMI as between 18.5 and 24.9. Below 18.5 is underweight; 25–29.9 is overweight; 30 and above is obese.
Is BMI accurate for everyone?
BMI is a useful screening tool but has limitations. It does not distinguish between muscle and fat, so athletes with high muscle mass may be incorrectly categorised as overweight. Age and ethnicity can also affect interpretation.
How do I convert pounds and feet to use this calculator?
Divide your weight in pounds by 2.205 to get kilograms. Multiply your height in feet by 30.48 to get centimetres (or inches by 2.54).
What should I do if my BMI is outside the healthy range?
Consult a healthcare professional. BMI is a starting point for conversation — not a diagnosis. A doctor can assess your full health picture.
What is Body Mass Index (BMI)?
The BMI formula and its origin
Body Mass Index was developed by Belgian mathematician Adolphe Quetelet in the 1830s as a simple way to assess population-level weight status. It remains the most widely used screening metric globally because it requires only weight and height — two measurements anyone can take at home.
BMI categories explained
The WHO defines four main categories: underweight (below 18.5), normal weight (18.5–24.9), overweight (25–29.9), and obese (30 and above). Some health organisations further split obesity into classes I, II, and III for clinical purposes.
Limitations of BMI
BMI does not measure body fat directly, nor does it account for fat distribution, age, sex, or ethnicity. A muscular person can have a high BMI despite low body fat. Asian populations may face higher health risks at lower BMI thresholds. Always combine BMI with other assessments such as waist circumference.
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →