BMI Calculator

Free BMI calculator. Enter your height and weight to calculate your Body Mass Index and see whether you are underweight, normal, overweight, or obese.

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BMI hesaplanacak
Category hesaplanacak
Healthy Weight Range hesaplanacak
BMI Prime hesaplanacak

What Is BMI?

Body Mass Index (BMI) is a simple numerical measure of body fat based on height and weight. It is widely used as a screening tool to identify weight categories that may lead to health problems, though it has limitations as it does not directly measure body fat or account for muscle mass.

BMI Formula

  • Metric: BMI = weight (kg) / height (m)²
  • Imperial: BMI = 703 × weight (lbs) / height (in)²

BMI Categories (WHO)

BMI RangeCategory
Below 18.5Underweight
18.5 – 24.9Normal weight
25.0 – 29.9Overweight
30.0 – 34.9Obese (Class I)
35.0 – 39.9Obese (Class II)
40.0 and aboveSeverely Obese (Class III)

Limitations of BMI

  • Does not distinguish muscle from fat — athletes may have a high BMI but low body fat.
  • Does not account for age-related changes in body composition.
  • May underestimate risk in people with low muscle mass (e.g., elderly).
  • Different thresholds may apply for different ethnic groups.

Better Indicators Alongside BMI

For a fuller picture of health, consider also measuring waist circumference (healthy: under 94 cm for men, 80 cm for women), waist-to-hip ratio, and body fat percentage.

How to Use This Calculator

Using our calculator is simple: enter the required values into the input fields and click the calculate button. Results are displayed instantly on screen. You can adjust the values and recalculate to compare different scenarios and find the best option for your situation.

Frequently Asked Questions

QuestionAnswer
How accurate are the results?We use standard formulas and up-to-date 2025 rates. Individual circumstances may vary slightly.
Is this calculator free?Yes, completely free and no registration required.
What should I do for exact figures?For precise information, consult a relevant professional or official authority.
Does it work on mobile devices?Yes, it works seamlessly on all devices and screen sizes.

Important Notes

This calculator is provided for informational purposes only. For legal, financial, or medical decisions, always seek advice from qualified professionals. Calculation results do not constitute official documents. Legislative changes may affect results; please visit the relevant official website for the most up-to-date information. Our calculators are regularly updated to reflect current regulations and rates.

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Frequently Asked Questions

A BMI between 18.5 and 24.9 is considered healthy for most adults. Below 18.5 is underweight; 25-29.9 is overweight; 30+ is obese.
BMI does not distinguish between muscle and fat mass. Athletes and very muscular people may have a high BMI but low body fat. It is a screening tool, not a diagnosis.
BMI Prime is BMI divided by 25 (the upper limit of normal). A value of 1.0 means you are exactly at the upper limit of normal weight.