Body Mass Index (BMI) Calculator
Calculate your Body Mass Index (BMI) and find out if your weight is healthy.
Notes:
- BMI is only a general indicator and does not take into account body composition.
- It does not distinguish between muscle mass and body fat.
- It may not be suitable for athletes, elderly people, children, or pregnant women.
- Always consult with a healthcare professional for a complete assessment.
What is Body Mass Index (BMI)?
Body Mass Index (BMI) is a measure that relates weight to height to assess whether a person has a healthy weight. It was developed by Belgian mathematician Adolphe Quetelet in the 19th century and has become a widely used tool in medicine and public health.
How BMI is calculated
BMI is calculated by dividing a person's weight (in kilograms) by the square of their height (in meters):
BMI = Weight (kg) / [Height (m)]²
For example, if you are 1.70 meters tall and weigh 70 kg, your BMI would be: 70 / (1.70)² = 70 / 2.89 = 24.22
BMI Categories according to WHO
The World Health Organization (WHO) establishes the following categories to interpret BMI in adults:
| Category | BMI (kg/m²) | Health Risk |
|---|---|---|
| Severe underweight | < 16.00 | Very high |
| Moderate underweight | 16.00 - 16.99 | High |
| Mild underweight | 17.00 - 18.49 | Moderate |
| Normal weight | 18.50 - 24.99 | Normal |
| Overweight | 25.00 - 29.99 | Increased |
| Obesity class I | 30.00 - 34.99 | High |
| Obesity class II | 35.00 - 39.99 | Very high |
| Obesity class III | ≥ 40.00 | Extremely high |
Limitations of BMI
Despite its widespread use, BMI has several important limitations:
- It does not distinguish between muscle mass, body fat, and bone structure
- It does not consider body fat distribution (abdominal fat is more dangerous than peripheral fat)
- It may not be suitable for athletes, very muscular people, elderly people, or children
- It does not account for ethnic or racial differences in body composition
- It does not provide information about other important health factors
For these reasons, BMI should be considered as an initial assessment tool, not as a definitive health diagnosis.
How to improve your BMI?
If your BMI is low
- Increase consumption of healthy calories
- Include high-quality proteins in every meal
- Consume healthy fats like avocado, nuts, and olive oil
- Perform strength training to increase muscle mass
- Consider nutritional supplements under medical supervision
- Eat frequently (5-6 small meals a day)
If your BMI is high
- Create a moderate caloric deficit (300-500 calories less)
- Increase protein intake to preserve muscle mass
- Prioritize whole foods, fruits, and vegetables
- Combine cardiovascular exercise and strength training
- Maintain adequate hydration
- Set realistic goals (0.5-1kg per week)
- Consider support from a healthcare professional
Other important health indicators
In addition to BMI, these are other indicators that can provide a more complete picture of your health:
Healthy habits to maintain an appropriate weight
- Balanced diet: Base your diet on fruits, vegetables, lean proteins, healthy fats, and whole grains.
- Regular physical activity: Try to perform at least 150 minutes of moderate activity or 75 minutes of intense activity per week.
- Adequate hydration: Drink enough water (approximately 2 liters daily).
- Quality rest: Sleep between 7-9 hours each night.
- Stress management: Practice relaxation techniques such as meditation, yoga, or deep breathing.
- Moderation with alcohol: Limit consumption of alcoholic beverages.
- Avoid tobacco: Smoking negatively affects almost all aspects of health.