Body Mass Index (BMI) Calculator

Calculate your BMI and understand your weight in relation to your height for better health management.

Calculate Your BMI

Metric Imperial
cm
kg

BMI Formula

Metric Formula:

BMI = weight(kg) / height²(m)

Imperial Formula:

BMI = (weight(lbs) × 703) / height²(in)

The Body Mass Index (BMI) is calculated by dividing your weight by the square of your height.

Your BMI Results

Fill in your height and weight to calculate your BMI

BMI Categories & Health Risk

BMI Range Category Health Risk
Below 18.5 Underweight Increased risk for nutritional deficiencies and osteoporosis
18.5 - 24.9 Normal weight Lowest risk for health problems
25.0 - 29.9 Overweight Increased risk for heart disease, high blood pressure, type 2 diabetes
30.0 and above Obesity High risk for heart disease, diabetes, metabolic syndrome, sleep apnea

Understanding BMI

What is BMI?

Body Mass Index (BMI) is a numerical value derived from a person's weight and height. It provides a simple way to categorize individuals based on their body mass, helping to identify potential weight issues.

BMI was developed by Belgian mathematician Adolphe Quetelet in the 1830s and has become the international standard for assessing weight status in adults.

BMI is a screening tool, not a diagnostic of body fatness or health. Further assessments by healthcare providers are necessary for a complete health evaluation.

Limitations of BMI

While BMI is useful for population-level assessments, it has several limitations:

  • Does not distinguish between muscle and fat mass
  • May overestimate body fat in athletes and muscular individuals
  • May underestimate body fat in older persons who have lost muscle mass
  • Different BMI cutoffs may be appropriate for different ethnic groups
  • Does not account for fat distribution (central vs. peripheral)

For a more comprehensive assessment, consider combining BMI with other measures like waist circumference or body composition analysis.

BMI and Health

BMI correlates with various health outcomes, with risks increasing at both ends of the BMI spectrum:

Health risks of low BMI (<18.5):

  • Malnutrition and nutrient deficiencies
  • Weakened immune system
  • Osteoporosis and bone fractures
  • Anemia
  • Hormone imbalances and fertility issues
  • Increased risk of surgical complications

Health risks of high BMI (>25):

  • Cardiovascular diseases (heart disease, stroke)
  • Type 2 diabetes
  • Hypertension (high blood pressure)
  • Certain types of cancer
  • Sleep apnea and breathing problems
  • Osteoarthritis and joint problems
  • Gallbladder disease

Remember: BMI is just one factor in assessing health. Physical activity level, diet quality, family history, and other clinical measures provide a more complete picture of health status.