BMI Calculator
Calculate Body Mass Index (BMI) and health risk classification based on WHO standards.
Input Parameters
Live Result
Details
Quick Answer & Understanding Your Result
Your Body Mass Index (BMI) is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m^2).
WHO Standard Adult BMI Categories
- Underweight: BMI less than 18.5 (increased risk of nutritional deficiency and osteoporosis).
- Normal / Healthy Weight: BMI 18.5 to 24.9 (lowest cardiovascular and metabolic disease risk).
- Overweight: BMI 25.0 to 29.9 (elevated risk of hypertension and type 2 diabetes).
- Obesity (Class I to III): BMI 30.0 and above (high risk of cardiovascular complications).
Asian-Pacific Adult BMI Criteria (WHO Western Pacific)
- Underweight: Less than 18.5
- Normal Range: 18.5 to 22.9
- Overweight / At Risk: 23.0 to 24.9
- Obese: 25.0 and above (due to higher visceral body fat percentage at lower BMI thresholds).
Enter your height and weight above to determine your exact BMI classification and optimal healthy weight target range.
Formula & Calculation Logic
Mathematical FormulaMetric: Divide weight in kilograms by height in meters squared. Imperial: Multiply weight in pounds by 703, then divide by height in inches squared.
Step-by-Step Guide
Select Unit System
Choose Metric (kg, cm) or Imperial (lbs, feet/inches).
Enter Height and Weight
Input your accurate current body weight and standing height.
Select Age and Biological Sex
Input demographic metrics for calibrated percentile interpretations.
Review BMI Score and Gauge
View your color-coded BMI gauge, weight category, and target healthy weight range.
Worked Examples Table
| Example | Input Values | Calculated Result | Explanation |
|---|---|---|---|
| Normal Weight Adult | 68 / (1.75)² = 22.2, falling within the healthy 18.5–24.9 WHO range. | ||
| Overweight Adult | 75 / (1.65)² = 27.5, indicating weight reduction is advisable. |
Frequently Asked Questions
Evidence-Based Methodology & Authoritative References
World Health Organization (WHO) - Body Mass Index Classification
CDC - Adult BMI Calculator & Health Guidelines
Standard: WHO Adult BMI Diagnostic Standard
Formula: BMI = Weight (kg) / [Height (m)]²
Last Reviewed: August 21, 2026
Primary Source: World Health Organization (WHO) - Body Mass Index Classification
Reference Document: CDC - Adult BMI Calculator & Health Guidelines
Computation Privacy: 100% client-side 0ms computation, zero data retention
Calculated health, metabolic, and biometric metrics are for general fitness and educational reference only. They do not substitute for professional medical advice, clinical diagnosis, or personalized treatment plans.
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Calculated results are modeled based on standard scientific and mathematical formulas. Please verify with domain-specific technical documentation for specialized applications.