Calculate your Body Mass Index and see your WHO health category.
BMI (Body Mass Index) is a simple screening tool that estimates body fat based on your height and weight. It was developed by Belgian mathematician Adolphe Quetelet in the 1830s and is still used worldwide by doctors and health organizations.
For a person weighing 70 kg with a height of 175 cm:
| BMI Range | Category | Health Risk |
|---|---|---|
| < 16.0 | Severe Thinness | Very High |
| 16.0 – 16.9 | Moderate Thinness | High |
| 17.0 – 18.4 | Mild Thinness | Moderate |
| 18.5 – 24.9 | Normal Weight | Low |
| 25.0 – 29.9 | Overweight | Moderate |
| 30.0 – 34.9 | Obese Class I | High |
| 35.0 – 39.9 | Obese Class II | Very High |
| ≥ 40.0 | Obese Class III | Extremely High |
* For Asian populations, overweight starts at BMI 23.0 and obese at 25.0 (WHO Asia-Pacific guidelines).
BMI is a useful screening tool, but it has limitations. It does not distinguish between muscle mass and fat mass.
| Factor | BMI | Body Fat % |
|---|---|---|
| Measures | Weight relative to height | Actual fat tissue |
| Accounts for muscle? | No | Yes |
| Equipment needed | None (scale + tape) | Calipers, DEXA, or BIA |
| Accuracy for athletes | Poor (overestimates) | Good |
| Best for | General health screening | Detailed body composition |
A healthy BMI range is 18.5 to 24.9 according to the World Health Organization. For Asian populations, the healthy range is narrower: 18.5 to 22.9.
No. BMI does not distinguish between muscle and fat. A muscular athlete with low body fat may have a high BMI and be classified as overweight despite being very healthy. Use body fat percentage instead.
The BMI formula itself doesn't account for age. However, body composition changes with age — older adults tend to have more body fat and less muscle. Some experts suggest slightly higher BMI ranges (25-27) may be acceptable for people over 65.
The BMI formula and categories are the same for both genders. However, women naturally have a higher body fat percentage than men (20-25% vs 15-20% for healthy adults).
Standard BMI categories apply to adults 20 and older. For children and teens (ages 2-19), BMI is interpreted using age-specific and sex-specific percentiles, which requires a different calculator.
Consult your doctor first. A combination of balanced diet, regular exercise (150+ min/week), adequate sleep, and stress management is recommended. Use our Calorie Calculator and TDEE Calculator to plan your approach.
BMI was developed by Belgian mathematician Adolphe Quetelet between 1830-1850. The term "Body Mass Index" was coined by Ancel Keys in 1972. Despite being nearly 200 years old, it remains the most widely used health screening metric.
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