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Advanced BMI
Calculator & Analyzer

Calculate your Body Mass Index, body fat %, ideal weight, calorie needs & health risks — all in seconds. Supports metric and imperial units.

✦ 10+ Health Metrics ✦ WHO Standards ✦ Body Fat Estimation ✦ Print & Share
📏 Your Measurements
years
cm
kg
cm
⚖️
Enter Your Details
Fill in your measurements and click Calculate to see your comprehensive BMI analysis.
🏥 Your Health Summary
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Adult
0.0
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018.52530354050
Healthy range: 18.5 – 24.9
📊 BMI-for-Age Percentile
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5th50th85th95th
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Based on CDC 2000 BMI-for-age growth charts. Percentile indicates relative position among same-age, same-gender peers.
📊 BMI Prime
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Ratio to upper healthy limit (25)
🧍 Ponderal Index
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Weight relative to height cubed
🔥 Daily Calories
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Estimated maintenance
💧 Body Fat %
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Estimated via BMI method
⚖️ Lean Mass
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Estimated fat-free mass
🎯 Healthy Weight Range
Your ideal range: —
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⚠️ Health Risk Assessment
💡 Personalized Recommendations
📋 Reference

BMI Classification Chart

WHO standard BMI categories for adults (20+ years).

Category BMI Range Risk Level
Severely Underweight < 16.0 Very High
Underweight 16.0 – 18.4 High
Normal (Healthy) 18.5 – 24.9 Low
Overweight 25.0 – 29.9 Moderate
Obese Class I 30.0 – 34.9 High
Obese Class II 35.0 – 39.9 Very High
Obese Class III ≥ 40.0 Extremely High
⚡ Features

Comprehensive Health Analysis

Advanced metrics beyond basic BMI for a complete picture of your health.

📊

10+ Health Metrics

BMI, BMI Prime, Ponderal Index, body fat %, lean mass, calorie needs, waist-to-height ratio and more.

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Dual Unit System

Switch seamlessly between Metric (kg/cm) and Imperial (lbs/ft) with instant conversion.

🎯

Ideal Weight Range

Visual bar showing your current weight against the healthy BMI range for your height.

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Risk Assessment

Color-coded health risk analysis based on WHO standards with actionable insights.

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Calorie Estimation

Mifflin-St Jeor equation for personalized daily calorie needs based on your profile.

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100% Private

All calculations run locally in your browser. Your data never leaves your device.

❓ FAQ

Frequently Asked Questions

BMI is calculated by dividing your weight in kilograms by the square of your height in meters: BMI = weight(kg) / height(m)². For Imperial units: BMI = 703 × weight(lbs) / height(inches)². This calculator performs both calculations with precision and provides additional derived metrics.
According to the World Health Organization (WHO), a healthy BMI for adults is between 18.5 and 24.9. Below 18.5 is considered underweight, 25–29.9 is overweight, and 30 or above is classified as obese. These ranges may vary slightly for different ethnicities and populations.
BMI may overestimate body fat in athletes and muscular individuals because it doesn't distinguish between muscle mass and fat mass. A muscular person may have a high BMI but low body fat percentage. Athletes should consider body fat percentage measurements (like DEXA scans or caliper tests) alongside BMI for a more complete picture.
Standard BMI applies to adults aged 20 and older. For children and teens (ages 2–19), BMI is calculated the same way but interpreted using age- and gender-specific percentiles. This calculator supports all ages 2–120 with automatic percentile-based BMI analysis for children using CDC growth charts, and standard WHO categories for adults.
BMI Prime is the ratio of your BMI to the upper limit of normal BMI (25). BMI Prime = your BMI / 25. A BMI Prime of 1.0 means you're at the upper boundary of the healthy range. Values below 0.74 indicate underweight, 0.74–1.0 are healthy, and above 1.0 indicates overweight or obesity.
The Ponderal Index (PI), also known as the Corpulence Index, uses height cubed instead of squared: PI = weight(kg) / height(m)³. It provides a more uniform measure across different heights and is considered more accurate for very tall or very short individuals. Normal range is typically 11–15.
This calculator uses the BMI-based body fat formula developed by Deurenberg et al.: Body Fat % = (1.20 × BMI) + (0.23 × Age) − (10.8 × Gender) − 5.4 (where Gender = 1 for male, 0 for female). This provides a reasonable estimate, though methods like DEXA scans or hydrostatic weighing are more precise.
Waist-to-height ratio (WHtR) is calculated by dividing waist circumference by height. A ratio below 0.5 is associated with lower cardiovascular risk. Research suggests WHtR may be a better predictor of heart disease risk than BMI alone, as it specifically targets abdominal fat distribution.