BMI Calculator

Calculate your Body Mass Index to assess your weight status

Height

Weight

Age

Gender

Result

BMI = 0 kg/m² (Normal)

Healthy BMI range: 18.5 kg/m² - 25 kg/m²
Healthy weight for the height: -
BMI Prime: -
Ponderal Index: - kg/m³

Personalized Health Recommendations

General Nutrition Tips:

Eat a variety of colorful fruits and vegetables
Choose whole grains over refined grains
Stay hydrated with water

Physical Activity:

Find activities you enjoy
Start slowly and build gradually
Stay consistent with your routine

BMI Information & Guidelines

Underweight

BMI less than 18.5

Normal Weight

BMI 18.5 - 24.9

Overweight

BMI 25 - 29.9

Obese

BMI 30 or greater

WHO BMI Classification Table for Adults (20+ years)

Classification	BMI Range (kg/m²)	Health Risk
Severe Thinness	< 16	High risk
Moderate Thinness	16 - 17	Moderate risk
Mild Thinness	17 - 18.5	Low risk
Normal	18.5 - 25	Minimal risk
Overweight	25 - 30	Increased risk
Obese Class I	30 - 35	Moderate risk
Obese Class II	35 - 40	High risk
Obese Class III	> 40	Very high risk

BMI Formula

Metric Units

BMI = weight (kg) / height (m)²

Example: 70 kg / (1.75 m)² = 22.9

Imperial Units

BMI = (weight (lbs) / height (in)²) × 703

Example: (154 lbs / (69 in)²) × 703 = 22.9

Risks of Being Overweight

High blood pressure
High LDL cholesterol, low HDL cholesterol
Type 2 diabetes
Coronary heart disease
Stroke
Gallbladder disease
Osteoarthritis
Sleep apnea and breathing problems
Certain cancers (endometrial, breast, colon)
Mental health issues

Risks of Being Underweight

Malnutrition and vitamin deficiencies
Anemia (reduced oxygen-carrying capacity)
Osteoporosis (weak bones)
Decreased immune function
Growth and development issues
Reproductive issues in women
Surgical complications
Increased mortality risk

BMI Limitations

Athletes & Muscular Individuals

BMI may overestimate body fat in athletes and those with high muscle mass, as muscle weighs more than fat.

Age Factor

Older adults tend to have more body fat than younger adults with the same BMI due to muscle loss.

Gender Differences

Women typically have more body fat than men at the same BMI due to biological differences.

Children & Teens

BMI calculations for children must account for age and gender using percentile charts.

Additional Health Metrics

BMI Prime

BMI Prime = BMI / 25

A dimensionless ratio where 1.0 represents the upper limit of normal BMI (25 kg/m²)

Ponderal Index

PI = mass (kg) / height³ (m)

More accurate for very tall or short individuals than BMI