⚖️ BMI Calculator
Calculate your Body Mass Index (BMI), ideal weight, body fat percentage and daily calories. Includes adult and children modes with WHO percentiles.
🧮 Calculator
📊 Your Result
💡 Interpretation
Enter your data above to see the interpretation.
🎯 Ideal Weight
🥑 Body Fat
🍎 Daily Calories
What is the Body Mass Index (BMI)?
The Body Mass Index (BMI) is an indicator that relates weight to height to estimate whether a person has an adequate weight. Developed by Belgian mathematician Adolphe Quetelet in the 19th century, it is used by the World Health Organization (WHO) as global reference.
The formula is simple: BMI = weight (kg) / height² (m²). Example: a person of 70 kg and 1.70 m has BMI of 70 ÷ (1.70 × 1.70) = 24.2.
WHO BMI Categories Table
| IMC | Category | Risk |
|---|---|---|
| < 18.5 | Underweight | Increased |
| 18.5 – 24.9 | Normal / Healthy | Low |
| 25.0 – 29.9 | Overweight | Increased |
| 30.0 – 34.9 | Obesity Class I | Moderate |
| 35.0 – 39.9 | Obesity Class II | High |
| ≥ 40.0 | Obesity Class III (Morbid) | Very high |
Ideal Weight, Body Fat and Calories
Ideal Weight
Ideal weight is the healthy weight range based on your height, calculated with BMI between 18.5 and 24.9.
Body Fat Percentage (Deurenberg Formula)
We estimate body fat percentage using the Deurenberg formula, which uses BMI, age and sex. It does not replace more precise measurements but is a good general estimate.
Daily Calories (Mifflin-St Jeor Formula)
Daily calories needed depend on your Basal Metabolic Rate (BMR) and physical activity level. We use the Mifflin-St Jeor formula.
BMI in Children and Adolescents
For children under 19, BMI is interpreted using percentiles by age and sex. A child with high BMI does not necessarily have overweight — must be compared to WHO growth charts.