What BMI can and cannot tell you
Body mass index is weight in kilograms divided by height in meters squared. It is a screening measure, not a diagnosis of health or body composition.
Worked example
Example: 70 kg at 175 cm gives a BMI of about 22.9. Standard adult categories may not apply to children or during pregnancy.
Assumptions and limitations
BMI does not directly measure body fat and can misclassify muscular individuals. Speak to a qualified clinician for personal advice.
How to use this calculator
Enter the requested values, check the units, and press Calculate now. Adjust one input at a time to compare scenarios. The result updates only when you press the button again.
For educational purposes only. Verify important financial or health decisions with a qualified professional.
BMI formula and interpretation
BMI = weight in kilograms ÷ (height in meters)². Adult screening categories often use 18.5 and 25 as reference cutoffs, but BMI does not measure body fat directly.
Frequently asked questions
Is BMI suitable for everyone?
No. BMI may be misleading for athletes, pregnant people and some other groups. It is not a medical diagnosis.
Can I use this calculator for free?
Yes. CalcTrustHub calculators are free to use and do not require an account. Results are estimates based on your inputs.
Understanding BMI limitations
BMI is a population-level screening measure based on height and weight. It does not directly measure body fat or distinguish muscle from fat. Adult BMI categories should not be applied uncritically to children, pregnant people or individuals for whom clinical context changes interpretation.
Is BMI a medical diagnosis?
No. A healthcare professional may consider waist measurements, medical history and other factors alongside BMI.