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BMI Calculator

Additional Metrics

  • Ideal Weight --
  • Weight to Gain/Lose --
  • Daily Calorie Needs --
  • Waist-to-Hip Ratio --

Your BMI

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Calculate BMI from Height and Weight

Calculate adult-style Body Mass Index (BMI) from height in centimetres and weight in kilograms. BMI is a screening measure, not a diagnosis. It does not directly measure body fat or describe a person’s complete health.

CalcMaster BMI Calculator
CalcMaster BMI Calculator

How to Use the BMI Calculator

  • Enter height in centimetres (cm).
  • Enter weight in kilograms (kg).
  • Use the age and gender fields for the calculator’s separate informational estimates. They do not change the BMI formula.
  • Select Calculate to see BMI and the displayed adult-style reference category.

This calculator is intended for adult-style reference categories. Children and teenagers require age- and sex-specific BMI-for-age assessment, so do not interpret their results with this page’s adult categories.

BMI Formula

The metric formula is:

BMI = weight in kilograms / (height in metres)2

Because the form accepts height in centimetres, it converts the value to metres before applying the formula. The displayed result is rounded to one decimal place.

Worked BMI Examples

  • 70 kg and 175 cm: 70 / 1.752 = 22.857…, displayed as 22.9.
  • 50 kg and 160 cm: 50 / 1.602 = 19.53125, displayed as 19.5.
  • 100 kg and 200 cm: 100 / 2.002 = 25.0, displayed as 25.0.

Adult BMI Reference Categories

The calculator uses these adult-style reference thresholds:

  • Below 18.5: Underweight
  • 18.5 to 24.9: Normal weight
  • 25.0 to 29.9: Overweight
  • 30.0 to 34.9: Obesity I
  • 35.0 to 39.9: Obesity II
  • 40.0 or above: Obesity III

A category is a screening reference, not a diagnosis and not a conclusion that a person is healthy or unhealthy. Discuss personal health concerns with a qualified healthcare professional.

Important BMI Limitations

  • BMI does not directly measure body fat and does not distinguish fat, muscle, and bone mass.
  • People with different body composition can have the same BMI and different health profiles.
  • Pregnancy, some medical conditions, and other circumstances may require a different assessment.
  • Children and teenagers need age- and sex-specific BMI-for-age interpretation rather than adult thresholds.

Use BMI as one general screening measure alongside other relevant health information. It should not be used by itself to make a medical decision.

Additional Calculator Estimates

The page may show separate informational estimates based on age, gender, height, and weight. These estimates are calculations, not clinical assessments, and should not be treated as personalized medical advice. The visible waist-to-hip field is not calculated because the form does not collect waist or hip measurements.

Common BMI Input Mistakes

  • Entering metres, feet, or inches when the form expects centimetres.
  • Entering pounds when the form expects kilograms.
  • Reading a category as a diagnosis or complete measure of health.
  • Using adult categories for a child or teenager.

Further Information

For source information about BMI calculation, adult interpretation, and limitations, see the CDC BMI FAQ and the NHS adult BMI guidance. For related CalcMaster tools, see the Unit Conversion Calculator, Simple Calculator, BMI calculator guide, and calculator categories.

FAQs

For most adults, a BMI between 18.5 and 24.9 is considered healthy.

No, BMI is just one of many tools. For a full picture of your health, consider also tracking body fat %, waist-to-hip ratio, activity levels, and diet habits.

If you're working on weight management or fitness goals, checking your BMI once every few weeks or monthly can help track progress. Otherwise, checking occasionally is enough for general awareness.

While BMI is a reliable general indicator of weight-related health risks, it doesn’t account for muscle mass or fat distribution. For better accuracy, pair it with a body fat percentage calculator.

No, you don't need to sign up. Our BMI calculator online is completely free to use, with no login or registration required.

Absolutely! Our BMI calculator is optimized for Indian users, but it also works globally. Whether you're calculating BMI in India, the US, or elsewhere, the results remain consistent.

Yes, the BMI formula is the same for both men and women. However, body composition (like muscle mass or fat percentage) can vary, so additional tools like a body fat calculator can offer more insights.

BMI is a useful screening tool, but it does not directly assess body fat or health. Athletes and those with high muscle mass may have a higher BMI but not excess fat.

Improving BMI involves a combination of healthy eating, regular physical activity, and lifestyle changes. Consult a healthcare provider for personalized advice.