Understanding BMI and Your Health
Body Mass Index (BMI) is a widely used tool to assess whether a person has a healthy body weight for their height. While it's not a perfect measure, it provides a quick screening method for weight categories that may lead to health problems.
What is BMI?
BMI is a calculation that uses your height and weight to estimate how much body fat you have. The formula is:
BMI = weight(kg) / height²(m²)Or for imperial measurements:
BMI = (weight(lb) / height²(in²)) × 703BMI Categories
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 - 24.9 | Normal weight |
| 25 - 29.9 | Overweight |
| 30 and above | Obesity |
Limitations of BMI
While BMI is a useful screening tool, it has several limitations:
- Doesn't distinguish between muscle and fat (athletes may have high BMI without excess fat)
- Doesn't account for fat distribution (abdominal fat is more dangerous)
- May not be accurate for certain ethnic groups or elderly individuals
- Doesn't consider sex differences in body composition
Other Health Indicators
For a more complete health assessment, consider these additional measures:
Waist Circumference
Excess abdominal fat is a risk factor for health problems:
- Men: Risk increases at >40 inches (102 cm)
- Women: Risk increases at >35 inches (88 cm)
Waist-to-Hip Ratio
Divide waist circumference by hip circumference:
- Men: Healthy if <0.9
- Women: Healthy if <0.85
Body Fat Percentage
A more direct measure of body composition:
| Category | Men | Women |
|---|---|---|
| Essential fat | 2-5% | 10-13% |
| Athletes | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average | 18-24% | 25-31% |
| Obese | 25%+ | 32%+ |
When to Consult a Doctor
If your BMI falls outside the normal range, or if you have concerns about your weight and health, consult with a healthcare professional. They can provide personalized advice and may recommend additional tests or lifestyle changes.
Use our BMI Calculator tool to check your BMI and learn more about what it means for your health.