Body Mass Index (BMI) & Health Risk Calculator
Compute accurate BMI using metric or imperial units, evaluate WHO weight classifications, analyze BMI Prime, and calculate Ponderal Index
Total body weight
Total height
Calculated Body Mass Index (BMI)
25.1 kg/m²
Overweight Classification (25.0 – 29.9)
Healthy Weight Range for Height: 136.4 lbs – 183.5 lbs
BMI Score
25.1 kg/m²
Weight ÷ Height Squared
Weight Status
Overweight
WHO clinical categorization
Healthy Weight Span
136 – 184 lbs
Corresponding to BMI 18.5 – 24.9
Disease Risk Factor
Increased
Relative comorbidity risk
Advanced Anthropometric Indices
BMI Prime Index
1.00
At Upper Limit of Normal Range
Ratio of Actual BMI to Upper Normal Limit (25.0) • Prime > 1.0 indicates overweight
BMI Prime Ratio
1.00
BMI ÷ 25.0 benchmark
Ponderal Index (PI)
12.6 kg/m³
Weight ÷ Height Cubed (Volumetric)
PI Normal Range
11.0 – 15.0 kg/m³
Standard volumetric body density
Height Independence
High Precision
Ponderal index scales better for height extremes
World Health Organization (WHO) BMI Classification Standards
Category
BMI Range (kg/m²)
Associated Health Risk
Severe Thinness< 16.0High Risk
Moderate Thinness16.0 – 16.9Medium Risk
Mild Thinness17.0 – 18.4Low Risk
Normal Weight18.5 – 24.9Lowest Risk (Optimal)
Overweight25.0 – 29.9Increased Risk
Obese Class I30.0 – 34.9High Risk
Obese Class II35.0 – 39.9Very High Risk
Obese Class III≥ 40.0Extremely High Risk
Clinical Limitation Note
BMI does not differentiate between body fat mass and lean muscle mass. Highly muscular athletes may register as overweight or obese despite having low body fat.