BMI Calculator
Calculate your Body Mass Index, see your weight category, and find your ideal weight range.
Your Measurements
Your BMI
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Category
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Weight Analysis
Ideal Weight Range
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Healthy BMI Range
18.5 - 24.9
Weight to Ideal
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BMI Categories
Saved Calculations
About This Calculator
BMI = weight (kg) / height (m)2. BMI is a screening tool, not a diagnostic. It does not distinguish between muscle and fat mass. Athletes, elderly, and pregnant individuals should consult healthcare providers for personalized assessments.
Formula source: The Body Mass Index formula was developed by Adolphe Quetelet and is recommended by the World Health Organization (WHO) as a population-level screening metric for weight classification.
BMI categories follow the WHO international classification: Underweight (<18.5), Normal (18.5-24.9), Overweight (25.0-29.9), Obese (30.0+).
Worked Example
Person: 5'10" (177.8 cm), 170 lbs (77.1 kg)
Step 1: Convert height to meters: 177.8 cm / 100 = 1.778 m
Step 2: Square the height: 1.778 x 1.778 = 3.161
Step 3: Divide weight by height squared: 77.1 / 3.161 = 24.4
Result: BMI of 24.4 falls in the "Normal Weight" category (18.5 - 24.9).
BMI Limitations
- BMI does not differentiate between lean muscle mass and body fat.
- Athletes and muscular individuals may be classified as overweight despite having low body fat.
- BMI may underestimate body fat in older adults who have lost muscle mass.
- BMI does not account for fat distribution. Central (abdominal) fat carries greater health risks than peripheral fat.
- For a more complete picture, consider measuring waist circumference, body fat percentage, or consulting your physician.
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Medical Disclaimer
This calculator is for informational and educational purposes only. It is not intended as medical advice, diagnosis, or treatment. BMI is a screening tool and does not diagnose body fatness or health. Always consult a qualified healthcare professional before making decisions about your health, diet, or exercise program.
Last reviewed: March 2026 | Sources: WHO BMI Classification, CDC Adult BMI Guidelines