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BMI Calculator

Estimate BMI and see the broad weight category for adults.

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Result Enter values to calculate.
Your result explanation will appear here.

Useful next checks

  • Treat the result as general guidance, not a diagnosis.
  • Check unusual results with a qualified health professional.
  • Retest with accurate measurements for a better estimate.

Intro

Use this BMI calculator to estimate adult body mass index from height and weight. BMI is a quick screening number that compares body weight with height, then places the result into a broad adult weight category.

What this BMI calculator does

Enter weight in kilograms and height in centimetres. The calculator converts height to metres, calculates BMI, and shows the broad category for the result.

BMI can be useful for a quick population-level screening, but it is not a complete measure of health. It does not directly measure body fat, muscle, fitness, or medical risk.

How it works

BMI is calculated as weight in kg / height in metres squared.

For example, a height of 175 cm is 1.75 m. The calculator squares the height, then divides body weight by that number.

Example calculation

A person who weighs 70 kg and is 175 cm tall has a height of 1.75 m. Squaring 1.75 gives 3.0625. Dividing 70 by 3.0625 gives a BMI of about 22.9.

For many adult screening charts, this falls in the normal range. Individual interpretation can vary by age, sex, ethnicity, muscle mass, pregnancy, and medical history.

How to use the result

Use BMI as a starting point, not a diagnosis. If the number is higher or lower than expected, consider other measurements and professional guidance. Waist measurement, body composition, activity level, blood pressure, blood markers, and symptoms can all matter.

For energy estimates, use the Calorie Calculator. For a body composition estimate, use the Body Fat Percentage Calculator.

Assumptions and limitations

  • This calculator is intended for adults.
  • It does not apply the age-specific charts needed for children and teens.
  • It does not measure body fat directly.
  • It may be less informative for athletes, older adults, pregnant people, or people with unusual body composition.
  • It is general health information, not medical advice.

FAQs

  • Is BMI a diagnosis? No. BMI is a screening estimate and should not be used alone to diagnose health.
  • Why can muscular people have a high BMI? BMI uses weight and height only, so it can count muscle mass the same way it counts fat mass.
  • Can children use this calculator? No. Children and teens need age- and sex-specific BMI charts.
  • What should I do with an unexpected result? Recheck the measurements, then consider speaking with a qualified health professional if you are concerned.

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Frequently asked questions

Is BMI a diagnosis?

No. BMI is a broad screening estimate and does not measure body composition or health directly.

Does BMI apply to children?

Children and teens need age-specific BMI charts, so this adult calculator is not suitable for them.