BMI Calculator

Calculate your Body Mass Index using metric or imperial units.

Healthy Weight Range
BMI Prime
Ponderal Index
Age Group
Underweight Normal Overweight Obese
<18.5 18.5 25 30+

How to use

  • Choose your units
    Select Metric if you know your weight in kilograms and height in centimeters. Select Imperial for pounds and feet/inches.
  • Enter your details
    Input your weight and height then click Calculate BMI.
  • Read your result
    Your BMI score and category will be displayed along with a visual scale showing where you fall.

BMI Categories

  • Under 18.5 Underweight
  • 18.5 – 24.9 Normal weight
  • 25 – 29.9 Overweight
  • 30 and above Obese

What is BMI?

Body Mass Index (BMI) is a simple measurement that uses your height and weight to estimate whether you have a healthy body weight. It was developed in the 1830s by Belgian mathematician Adolphe Quetelet and is still widely used today as a quick screening tool by doctors and health professionals worldwide.

How is BMI Calculated?

BMI is calculated by dividing your weight in kilograms by the square of your height in meters. For example, a person who weighs 70 kg and is 1.75 m tall has a BMI of 70 ÷ (1.75 × 1.75) = 22.9, which falls in the normal range.

Limitations of BMI

While BMI is a useful starting point, it does not account for muscle mass, bone density, age, or gender. Athletes may have a high BMI due to muscle rather than fat. Always consult a healthcare professional for a complete assessment of your health.

Frequently Asked Questions

What is a healthy BMI?

A BMI between 18.5 and 24.9 is considered healthy for most adults. However, this range may vary slightly by age and ethnicity.

Is BMI accurate for children?

BMI for children is calculated differently — it uses age and gender-specific charts. This calculator is designed for adults aged 18 and above.

Can I have a normal BMI but still be unhealthy?

Yes. BMI is just one indicator. Factors like diet, exercise, sleep, and stress all play a role in overall health regardless of BMI score.

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