BMI Calculator
Body Mass Index with WHO classification and ideal weight range
Enter Details
kg
cm
Results
⚖️
Enter your weight and height to calculate BMI.
Formula
BMI = weight (kg) ÷ height² (m)
- weight (kg) — Body weight in kilograms
- height (m) — Height in metres (cm ÷ 100)
Example: 70 kg ÷ 1.75² = 70 ÷ 3.0625 ≈ 22.9
Interpreting Your Result
< 18.5
Underweight
May indicate insufficient nutrition
18.5–24.9
Normal weight
Lowest health risk
25.0–29.9
Overweight
Increased metabolic risk
≥ 30.0
Obese
High cardiovascular risk
Frequently Asked Questions
What is BMI?
BMI (Body Mass Index) is a number from weight and height used to screen for weight categories linked to health problems.
What is a healthy BMI?
18.5–24.9 is normal weight by WHO. Below 18.5 is underweight; 25–29.9 is overweight; 30+ is obese.
Is BMI accurate for athletes?
No. BMI can't distinguish muscle from fat. Athletes with high muscle mass may show high BMI despite healthy body composition — use Body Fat % alongside it.
Does BMI differ by ethnicity?
Yes. For South Asians, health risks begin at lower thresholds. Many guidelines use 23.0 as the overweight cutoff for Indian adults.