Is BMI the same as body-fat percentage?
No. BMI uses only height and weight. It does not directly measure body fat or muscle mass.
Calculator Tools
BMI Calculator Online Free
Calculate Body Mass Index using height and weight. Review the general adult screening category together with the formula, practical limits and guidance for interpreting the result responsibly.
Adult BMI screening workspace
Use metric or imperial units and see the general adult BMI category and weight range for your height. BMI is a screening measure, not a diagnosis.
Practical guide
About BMI Calculator
Body Mass Index compares body weight with height to provide a general screening value for adults. It is widely used because the inputs are simple, but BMI is not a direct measurement of body fat, fitness or medical health. Muscular people, older adults, pregnant people and children may require different interpretation. The calculator converts height from centimetres to metres, squares that value and divides weight in kilograms by the result. It then displays the commonly used BMI category. The output is most useful as a starting point for discussion rather than a diagnosis or personal treatment recommendation.
Formula or Calculation Logic
BMI = Weight in kilograms ÷ Height in metres²
Example: 70 ÷ (1.75 × 1.75) = 22.86
Practical Example
Height: 175 cm
Weight: 70 kg
BMI: 22.9
General adult screening category: normal range
Common Uses
- ✓Obtaining a quick adult weight-to-height screening value
- ✓Tracking a general change over time alongside other measurements
- ✓Preparing for a discussion with a qualified health professional
- ✓Learning how the BMI formula works
Common Mistakes
- ✓Treating BMI as a diagnosis
- ✓Using centimetres directly in the metre-based formula
- ✓Applying adult categories to children without age-specific charts
- ✓Ignoring muscle mass, pregnancy, age and body composition
Good Practice
- ✓Use accurate height and weight measurements
- ✓Interpret BMI together with medical history and other health indicators
- ✓Use age-appropriate professional guidance for children and teenagers
- ✓Seek qualified advice when the result raises a health concern
How to Use This Calculator
- 1Enter height in centimetres.
- 2Enter weight in kilograms.
- 3Review the calculated BMI and general adult category.
- 4Use the result as screening information, not as a medical diagnosis.
Privacy and Result Checking
Height and weight are processed locally in your browser and are not uploaded to FormatForge.
Important: BMI is a general screening measure and not medical advice. Individual health assessment should come from a qualified professional.
Frequently Asked Questions
Can athletes have a high BMI?
Yes. Higher muscle mass can increase weight and BMI even when body-fat levels are not high.
Can this calculator be used for children?
Children and teenagers require age- and sex-specific growth charts interpreted by an appropriate professional.
What units does the calculator use?
The current calculator accepts height in centimetres and weight in kilograms.