How is BMI calculated?

BMI is calculated as weight in kilograms divided by height in metres squared (kg/m²). In imperial mode, the formula is (weight in lbs × 703) / (height in inches)².

What do the BMI categories mean?

Underweight: below 18.5. Normal weight: 18.5–24.9. Overweight: 25–29.9. Obese: 30 and above. These are WHO standard thresholds for adults.

Is BMI accurate for everyone?

BMI is a general screening tool and does not account for muscle mass, age, sex, or ethnicity. Athletes may have a high BMI despite low body fat. Always consult a healthcare professional for a full health assessment.

Can I use feet and inches instead of centimetres?

Yes — toggle to Imperial mode to enter height in feet and inches and weight in pounds. The BMI result and category remain the same.

BMI Calculator

Calculate your Body Mass Index (BMI) with metric or imperial units and see your WHO category.

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Weight (kg)

Height (cm)

How to BMI Calculator

Choose Metric (kg/cm) or Imperial (lbs/ft & in).
Enter your height and weight.
Your BMI is calculated instantly and displayed with a visual gauge.
The result shows your WHO category: Underweight, Normal, Overweight, or Obese.

Why Use This Tool?

BMI is a widely-used screening tool to identify potential weight-related health risks. While it does not account for muscle mass or body composition, it provides a quick reference point used by healthcare professionals worldwide. This tool uses the standard WHO thresholds and supports both metric and imperial input.

BMI Calculator

How to BMI Calculator

Why Use This Tool?

Frequently Asked Questions