BMI Calculator

Calculate BMI and check your health category

Enter your height and weight to calculate your BMI

What is BMI?

Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. BMI is a useful measure of overweight and obesity for most people aged 18-65 years.

BMI is used as a screening tool to identify whether an adult is at a healthy weight. It's quick, easy, and inexpensive to calculate, making it one of the most widely used methods to assess weight categories.

How is BMI Calculated?

BMI is calculated by dividing your weight in kilograms by your height in meters squared:

BMI = weight (kg) ÷ height² (m²)

For imperial units, the formula is:

BMI = (weight (lb) ÷ height² (in²)) × 703
BMI Categories

The World Health Organization (WHO) defines the following BMI categories for adults:

CategoryBMI Range
UnderweightBelow 18.5
Normal Weight18.5 - 24.9
Overweight25 - 29.9
Obese30 and above
Limitations of BMI

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

  • It doesn't distinguish between muscle and fat mass. Athletes may have a high BMI due to muscle.
  • It doesn't account for fat distribution, which affects health risks.
  • It may not be accurate for elderly individuals who have lost muscle mass.
  • Different ethnic groups may have different health risks at the same BMI.

BMI should be used as one of several tools when assessing health. Consult a healthcare provider for a comprehensive health evaluation.

Frequently Asked Questions

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