Understanding BMI: What Your Number Really Means

What is BMI?

Body Mass Index (BMI) is a simple calculation using height and weight: weight (kg) / height² (m²). It was designed in the 1830s as a quick way to assess population health.

The BMI Categories

• Under 18.5: Underweight
• 18.5 - 24.9: Normal weight
• 25 - 29.9: Overweight
• 30+: Obese

Limitations of BMI

• Ignores Muscle: Athletes often have "overweight" BMIs due to muscle mass.
• Age Blind: Doesn't account for body composition changes with age.
• No Fat Distribution: Belly fat is more dangerous than hip fat, but BMI can't tell the difference.

Better Alternatives

Consider waist-to-hip ratio, body fat percentage, or waist circumference alongside BMI for a fuller picture.

Calculate your BMI instantly with our BMI Calculator.