BMI is a useful screening tool but doesn't distinguish between muscle and fat. Athletes may have high BMI due to muscle. Use BMI alongside other measurements like waist circumference.

What is a healthy BMI?

A healthy BMI is between 18.5 and 24.9. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese.

Understanding BMI: What Your Body Mass Index Really Means

BMI (Body Mass Index) is one of the most commonly used health metrics. But what does it actually measure, and how should you interpret your results?

What is BMI?

BMI is a simple calculation based on your weight and height:

BMI = Weight (kg) ÷ Height (m)²

It's used as a quick screening tool to categorize people into weight status categories.

BMI Categories

Underweight: BMI below 18.5
Normal weight: BMI 18.5 - 24.9
Overweight: BMI 25 - 29.9
Obese: BMI 30 or higher

Example Calculation

For someone who is 175 cm (1.75 m) tall and weighs 70 kg:

BMI = 70 ÷ (1.75)² = 70 ÷ 3.0625 = 22.9

This falls in the "Normal weight" category.

Limitations of BMI

BMI has several limitations:

It doesn't distinguish between muscle and fat
It doesn't account for fat distribution
It may not be accurate for athletes or elderly
It doesn't consider bone density

Better Health Metrics

For a more complete picture, combine BMI with:

Waist circumference: Less than 40 inches for men, 35 for women
Waist-to-hip ratio: Less than 0.9 for men, 0.85 for women
Body fat percentage: Measured with calipers or DEXA scan
Blood markers: Cholesterol, blood sugar, blood pressure

Try Our Calculator

Want to check your BMI? Use our free BMI Calculator to calculate your Body Mass Index and see if your weight is in a healthy range.