Efficient BMI Calculator: Track Your Health & Fitness Status

A user-friendly BMI (Body Mass Index) calculator that helps assess body weight status based on height and weight. Features include US/metric units, visual gauge display, healthy weight ranges, and detailed health insights. Perfect for personal health monitoring and fitness tracking.

ages: 2 - 120
feet
inches
centimeters
(30-250 cm)
pounds
kilograms
BMI Result
Healthy BMI Range
Healthy Weight Range
BMI Prime
Ponderal Index

Learn More About BMI

What is BMI?

BMI (Body Mass Index) is a widely used measurement that helps assess whether a person has a healthy body weight for their height. It serves as a screening tool to identify potential weight-related health issues.

BMI = weight(kg) / height²(m) or BMI = 703 × weight(lbs) / height²(inches)
Key Points to Remember
  • BMI is an estimate that cannot account for body composition
  • It should be used alongside other health measurements
  • Different BMI ranges apply to children and teens
  • BMI calculations may need adjustment for certain populations

BMI Classification Tables

BMI Table for Adults (Age 20+) (20+)
Classification BMI Range (kg/m²)
Severe Thinness < 16
Moderate Thinness 16 - 17
Mild Thinness 17 - 18.5
Normal 18.5 - 25
Overweight 25 - 30
Obese Class I 30 - 35
Obese Class II 35 - 40
Obese Class III > 40
Health Implications
Risks of Being Overweight
  • High blood pressure and cholesterol issues
  • Type II diabetes
  • Heart disease and stroke risks
  • Osteoarthritis and joint problems
  • Sleep apnea and breathing difficulties
  • Increased risk of certain cancers
Risks of Being Underweight
  • Malnutrition and vitamin deficiencies
  • Weakened immune system
  • Osteoporosis and bone fragility
  • Growth and development issues
  • Reproductive health problems
  • Increased surgical complications

Limitations of BMI

Important Considerations

BMI is a screening tool, not a diagnostic measure. The following factors can affect BMI accuracy:

  • Older adults tend to have more body fat
  • Women generally have higher body fat
  • Children require age-specific calculations
Body Composition
  • Doesn't distinguish between fat and muscle
  • Athletes may show as "overweight"
  • Cannot measure fat distribution
Other Factors
  • Ethnic variations not considered
  • Pregnancy affects measurements
  • Height extremes can skew results

Frequently Asked Questions

BMI (Body Mass Index) is a numerical value of your weight in relation to your height. It's an important screening tool used to identify potential weight problems in adults and is widely used by health professionals.

BMI doesn't directly measure body fat and may not be accurate for athletes, elderly people, or those with high muscle mass. It should be used as one of several tools to assess health, not as a sole indicator.

BMI Prime is your BMI divided by 25 (the upper limit of normal BMI). A BMI Prime of 1.0 means you're at the upper limit of normal weight. Values less than 1.0 indicate underweight or normal weight, while values greater than 1.0 indicate overweight or obesity.