BMI Calculator (Body Mass Index)
Body Mass Index is a screening screening metric that relates weight to height. While useful for population-level health assessments, it does not directly measure body fat percentage or muscle composition.
Calculated Result
Enter values to view result
Notice: Body Mass Index is a general screening indicator, not a medical diagnosis. It does not account for muscle mass, bone density, age, gender, or distribution of body fat. Consult a certified healthcare provider for individualized health advice.
Formula & Mechanics
Metric: BMI = Weight (kg) / [Height (m)]²
Imperial: BMI = 703 × Weight (lbs) / [Height (in)]²
Divide weight in kilograms by the square of height in meters. In imperial units, multiply the weight-to-height ratio by 703.
Worked Step-by-Step Example
Scenario: A person weighs 72 kg and stands 1.75 meters tall.
- Height squared: 1.75 × 1.75 = 3.0625
- Divide weight: 72 ÷ 3.0625 ≈ 23.51
BMI is 23.5 (Normal weight category).
Frequently Asked Questions
What are the standard WHO BMI categories?
Underweight: < 18.5; Normal weight: 18.5 – 24.9; Overweight: 25.0 – 29.9; Obesity: ≥ 30.0.
Why might an athletic person have an elevated BMI?
Dense skeletal muscle weighs more than fat tissue of the same volume. Muscular athletes may test in the "overweight" range despite having low body fat.
Related Calculators
Running Pace Calculator
Calculate your average running pace per kilometer or mile from workout distance and elapsed time.
Open →Speed, Distance & Time Calculator
Solve for speed, travel distance, or transit duration in vehicular, cycling, or pedestrian scenarios.
Open →