BMI Calculator
Calculate BMI (Body Mass Index) from height and weight automatically and display obesity classification. Useful for health management, diet, and medical checkups.
Calculation Result
Please enter height and weight
BMI Classification Table
| BMI Range | Classification |
|---|---|
| Below 18.5 | Underweight |
| 18.5 - 24.9 | Normal weight |
| 25.0 - 29.9 | Overweight |
| 30.0 - 34.9 | Obesity Class I |
| 35.0 - 39.9 | Obesity Class II |
| 40.0 and above | Obesity Class III |
How to Use
- STEP 1
- Enter height (cm) and weight (kg), then click 'Calculate BMI' button for automatic calculation.
- STEP 2
- The result displays both BMI value and obesity classification.
- STEP 3
- Reference BMI classification table is also available for reference.
Important Notes
- BMI is calculated from height and weight only and does not consider muscle mass or body fat percentage.
- May not be applicable for pregnant women, growing children, or athletes with high muscle mass.
- BMI is only a reference indicator. Consult a doctor for detailed health assessment.
- This tool is for health management reference and does not replace medical diagnosis.
Tips
BMI was developed by Belgian mathematician Adolphe Quetelet in 1832 and has been widely used as a health indicator.
The ideal BMI of 22 is statistically associated with the lowest mortality rate according to large-scale epidemiological studies.
BMI calculation is simple but effective for population-level obesity assessment and health policy formulation.
WHO classifies BMI ranges as: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese (≥30).
BMI is calculated the same way worldwide, making it useful for international comparisons of obesity prevalence.
FAQ
QUESTION 1
What is BMI?
Body Mass Index is an international indicator for assessing obesity level from height and weight. Formula: weight(kg) ÷ height(m)²
QUESTION 2
What are the BMI standards?
WHO standards consider 18.5-24.9 as 'normal weight'. However, standards may vary by race and age.
QUESTION 3
What happens if BMI is high/low?
High BMI may increase risk of lifestyle diseases, while low BMI may increase risk of malnutrition or weakened immunity.
QUESTION 4
Can BMI alone determine health?
BMI is a simple indicator. Comprehensive health management considering body fat, muscle mass, age, and gender is important.
QUESTION 5
What's the ideal BMI value?
Generally 22 is considered ideal, but individual differences exist. Consult a doctor to set your target value.
This information is general guidance. Consult doctors or medical institutions for detailed advice.