Advanced BMI Calculator
Calculate BMI with Health Risk Assessment & Personalized Recommendations
About BMI
Body Mass Index (BMI) is a measure of body fat based on your weight in relation to your height. It applies to most adult men and women aged 20 and over. While BMI is a useful screening tool, it doesn't directly measure body fat or account for muscle mass, bone density, or body composition.
Enter Your Details
Your BMI Analysis
Your BMI falls within the normal weight range for your height.
BMI Scale
<18.5 Normal
18.5–24.9 Overweight
25–29.9 Obese
30–34.9 Extreme Obese
≥35
Health Risk Assessment
Personalized Recommendations
BMI Distribution
BMI & Health Risks
Understanding the health risks associated with different BMI categories can help you make informed decisions about your health and wellness journey.
Health Risks by BMI Category
Underweight (BMI < 18.5)
• Malnutrition and nutrient deficiencies • Osteoporosis • Decreased immune function • Fertility issues • Increased surgical risk
Normal Weight (BMI 18.5–24.9)
• Lowest health risks • Reduced risk of chronic diseases • Better physical function • Improved mental health • Longer life expectancy
Overweight (BMI 25–29.9)
• Increased risk of type 2 diabetes • Higher blood pressure • Elevated cholesterol • Joint problems • Sleep apnea
Obese (BMI ≥ 30)
• Heart disease and stroke • Certain cancers • Severe breathing problems • Gallbladder disease • Osteoarthritis
Relative Risk Increase
Heart Disease
Overweight: 2x risk
Obese: 3-4x risk
Type 2 Diabetes
Overweight: 3x risk
Obese: 7x risk
Sleep Apnea
Overweight: 4x risk
Obese: 10x risk
Osteoarthritis
Overweight: 2x risk
Obese: 4x risk
BMI Categories & Classification
The World Health Organization (WHO) defines standard BMI categories for adults. These categories are based on statistical data relating BMI to health risks.
WHO BMI Classification
| Category | BMI Range (kg/m²) | Health Risk | Action Required |
|---|---|---|---|
| Underweight | < 18.5 | Increased | Nutrition consultation, weight gain program |
| Normal Weight | 18.5 – 24.9 | Lowest | Maintain healthy lifestyle |
| Overweight | 25 – 29.9 | Increased | Moderate weight loss, lifestyle changes |
| Obese Class I | 30 – 34.9 | High | Weight loss program, medical supervision |
| Obese Class II | 35 – 39.9 | Very High | Medical intervention, supervised program |
| Obese Class III | ≥ 40 | Extremely High | Urgent medical treatment |
Limitations of BMI
While BMI is a useful screening tool, it has limitations:
- Doesn't distinguish between muscle and fat
- May overestimate body fat in athletes
- May underestimate body fat in older adults
- Doesn't account for fat distribution
- Not suitable for children, pregnant women, or certain ethnic groups
Alternative measurements: Waist circumference, waist-to-hip ratio, body fat percentage, and DEXA scans provide more comprehensive assessments.

