Free BMI Calculator
What is BMI?
Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to adult men and women.
Key applications: Health screening, fitness assessment, weight management, medical research, insurance evaluations.
Formula: BMI = weight (kg) / [height (m)]²
Example: 70kg / (1.75m)² = 22.86 (Normal weight)
Example: 70kg / (1.75m)² = 22.86 (Normal weight)
Basic BMI Calculator
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BMI calculation will appear here.
BMI with Categories
Calculate BMI and get health category.
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BMI category will appear here.
Ideal Weight Estimator
Estimate ideal weight range based on height.
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Ideal weight estimation will appear here.
BMI Categories Reference Chart
<18.5
Underweight
May need to gain weight
18.5-24.9
Normal
Healthy weight range
25-29.9
Overweight
May need to lose weight
30-34.9
Obese Class I
Moderate obesity
35-39.9
Obese Class II
Severe obesity
>=40
Obese Class III
Very severe obesity
BMI Calculator Examples
Example 1: Normal Weight
Problem: 70kg, 175cm
Solution: BMI = 22.86 (Normal)
Use Case: Fitness check
Example 2: Overweight
Problem: 90kg, 170cm
Solution: BMI = 31.14 (Obese Class I)
Use Case: Health screening
Example 3: Imperial Units
Problem: 154lbs, 5'5" (65in)
Solution: BMI = 25.6 (Overweight)
Use Case: US measurements
Example 4: Ideal Weight
Problem: 180cm, Male
Solution: Ideal range: 60-81kg (BMI 18.5-24.9)
Use Case: Weight goal setting
How to Calculate BMI: Complete Guide
Method 1: Metric System
- Measure weight in kg
- Measure height in m
- Calculate: weight / (height × height)
- Example: 65 / (1.6 × 1.6) = 25.39
Method 2: Imperial System
- Weight in lbs, height in inches
- Calculate: (weight × 703) / (height × height)
- Example: (150 × 703) / (65 × 65) = 24.96
- Convert if mixed units
Method 3: Categories Assessment
- Calculate BMI value
- Compare to categories chart
- Consider age/gender adjustments
- Consult professional if needed
Method 4: Ideal Weight
- Choose BMI range (18.5-24.9)
- Min weight = 18.5 × height²
- Max weight = 24.9 × height²
- Adjust for frame size
Real-World Applications of BMI
🏥 Health & Medicine
- Risk assessment
- Weight management
- Nutritional planning
- Disease screening
💪 Fitness & Sports
- Body composition
- Training goals
- Athlete classification
- Progress tracking
📊 Research & Statistics
- Population studies
- Obesity trends
- Epidemiology
- Public health
🏢 Insurance & Workplace
- Premium calculations
- Wellness programs
- Health incentives
- Risk evaluation