BMI Calculator

Calculate your Body Mass Index (BMI) instantly. Supports both Metric (kg/cm) and Imperial (lbs/ft) units.

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About BMI Calculator

What is BMI?

Body Mass Index (BMI) is a numerical value calculated from a person's weight and height. It provides a simple screening method to categorize individuals into weight status categories that may indicate potential health risks.

BMI Formula

The formula for BMI is straightforward:

  • Metric: BMI = weight (kg) ÷ height² (m²)
  • Imperial: BMI = (weight (lbs) × 703) ÷ height² (inches²)

BMI Categories

BMI Range Category
Below 18.5 Underweight
18.5 – 24.9 Normal Weight
25.0 – 29.9 Overweight
30.0 and above Obese

Limitations of BMI

While BMI is a useful screening tool, it has important limitations:

  • It does not measure body fat directly and cannot distinguish between fat and muscle mass.
  • Athletes with high muscle mass may be classified as "overweight" despite being very fit.
  • It does not account for age, gender, ethnicity, or body composition.
  • Always consult a healthcare professional for a comprehensive health assessment.

Frequently Asked Questions

What is a healthy BMI range?

A BMI between 18.5 and 24.9 is considered "Normal Weight." Below 18.5 is "Underweight," 25.0–29.9 is "Overweight," and 30.0 or above is classified as "Obese." However, BMI does not account for muscle mass or body composition.

Is BMI accurate for athletes?

BMI may overestimate body fat in athletes and people with high muscle mass since muscle weighs more than fat. For a more accurate assessment, consult a healthcare professional who can measure body fat percentage directly.