BMI Calculator
Calculate your Body Mass Index (BMI) based on height and weight to determine your weight category and potential health risks.
※ Use if necessary
BMI Calculator
Calculate your Body Mass Index (BMI) to assess your weight category and potential health risks based on your height and weight.
These results are for reference only and were developed for educational and testing purposes. You can also directly access and review the source code, including the logic and free APIs used on this page.
BMI Results
BMI Calculator Guide
The Body Mass Index (BMI) is a simple calculation using a person's height and weight to screen for weight categories that may lead to health problems. This guide provides instructions on using the calculator and objective information about BMI.
How to Use the BMI Calculator
Follow these steps to calculate your BMI:
- Enter Your Height: Input your height in centimeters, inches, or feet.
- Enter Your Weight: Input your weight in kilograms or pounds.
- Optional Information: Provide your age and gender for more accurate assessment (optional).
- Calculate: Click "Calculate BMI" to view your results.
Understanding BMI
BMI is a screening tool that estimates body fat based on height and weight measurements.
BMI Formula
The standard BMI formula is:
- Metric units: BMI = weight (kg) / (height (m))²
- Imperial units: BMI = 703 × weight (lb) / (height (in))²
BMI Categories
According to the World Health Organization (WHO):
- Underweight: BMI less than 18.5
- Normal weight: BMI 18.5 to 24.9
- Overweight: BMI 25 to 29.9
- Obesity Class I: BMI 30 to 34.9
- Obesity Class II: BMI 35 to 39.9
- Obesity Class III: BMI 40 or greater
Limitations of BMI
While BMI is a useful screening tool, it has limitations:
Does Not Measure Body Fat Directly
BMI does not distinguish between fat, muscle, and bone mass.
- May overestimate body fat in muscular individuals
- May underestimate body fat in older adults who have lost muscle mass
Other Factors to Consider
Additional measurements provide more complete health assessment:
- Waist circumference
- Body fat percentage
- Blood pressure and cholesterol levels
- Diet and physical activity
Health Risks Associated with BMI
BMI categories correlate with certain health risks:
Underweight (BMI < 18.5)
- Nutritional deficiencies
- Osteoporosis
- Decreased immune function
Overweight (BMI 25-29.9)
- Increased risk for type 2 diabetes
- High blood pressure
- Cardiovascular disease
Obesity (BMI ≥ 30)
- Severe risk for chronic diseases
- Increased mortality risk
- Joint problems and mobility issues
BMI for Different Populations
BMI interpretation may vary for specific groups:
Children and Teens
- BMI-for-age percentiles are used
- Growth patterns differ by age and sex
- CDC growth charts are standard reference
Older Adults
- BMI range of 23-27 may be optimal
- Higher BMI may be protective against osteoporosis
Athletes
- Muscle mass may result in high BMI without excess fat
- Body composition tests are more accurate
Final Tips for Using the Calculator
- Measure height and weight accurately without shoes.
- Use the calculator as a general screening tool only.
- Consult a healthcare provider for comprehensive assessment.
- Combine BMI with other health indicators for complete picture.
This calculator provides estimates based on standard formulas. Individual health assessment requires professional medical evaluation.