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BMI Calculator

Calculate your body mass index (BMI) and get an instant classification of your weight range.

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BMI (body mass index) is a simple metric that relates body weight to height. It is commonly used as a first indicator to classify underweight, normal weight or overweight.

UnitsChoose metric, US or UK units for distance, area, volume and car consumption.
lb
Enter the value for “Weight” here. Use realistic assumptions so the result remains meaningful.
in
Enter the value for “Height” here. Use realistic assumptions so the result remains meaningful.
Guidance

BMI Calculator: Use BMI responsibly as rough orientation

Health calculators provide orientation, not diagnosis. Use the result as a starting point and consider age, body composition, activity and individual context.

How to use the result better

  • Treat the result as an estimate, not a medical judgment.
  • Compare several values rather than one metric only.
  • Seek medical advice if you have symptoms or uncertainty.

Common mistake

One formula value cannot fully represent individual differences. Body composition, lifestyle and health can vary strongly.

Is this medical advice?

No. It provides orientation and does not replace diagnosis, treatment or medical advice.

Why can values differ?

Formulas use averages. Body composition, activity, age and health can lead to different results.

Next steps

Useful calculators to continue

After the result, related calculators help you understand costs, alternatives and next steps more clearly.

GuideBMI explained: weight, height and health contextThe key points are orientation values and interpretation. Do not rely on one isolated value. Compare multiple scenarios to understand the effect of daily routines, goals and realistic limits.
Put values in contextUse results as guidance, not as a medical diagnosis.
See connectionsCompare related health values for a clearer overall picture.
Act more consciouslyThe calculators support everyday assessment and planning.

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How to use the result well

  • Compare several scenarios: Change the key values and check how much the result changes.

  • Use related calculators: Decisions often become clearer when you also calculate costs, timeframes or alternatives.

More Health calculatorsFind additional tools that fit this calculation topic.
Formula

How the result is calculated

BMI = weight in kg / (height in m × height in m)

Example

Worked example

Example: A person with 75 kg and 1.80 m has a BMI of about 23.1, which is within the normal range.

What does BMI indicate?

BMI relates body weight to height and provides a quick classification of whether your weight is within a typical range.

Limitations of BMI

BMI does not account for muscle mass, fat distribution or individual differences. Athletic people may have a high BMI without being overweight.

When is BMI useful?

BMI is useful as a quick guideline or starting point. For deeper insights, additional measurements are recommended.

FAQ

Frequently asked questions

Is BMI accurate?

It is a useful guideline, but not a precise health assessment.

What is a normal BMI?

The normal range is roughly between 18.5 and 24.9.

Why is muscle mass an issue?

Because muscle weighs more than fat and can increase BMI without indicating overweight.

Disclaimer

Important information

BMI is a simplified indicator and does not account for body composition, muscle mass or individual differences.