Health
BMI Calculator — Body Mass Index with Category, Free & Private
Calculate your Body Mass Index and see your weight category (underweight, normal, overweight, obese) based on WHO guidelines. Supports metric and imperial. Runs in your browser — no data sent anywhere.
Frequently Asked Questions
- What is BMI?
- Body Mass Index (BMI) is a measure of body fat based on height and weight. It is calculated as weight (kg) / height² (m²).
- What are the BMI categories?
- Under 18.5: Underweight. 18.5–24.9: Normal weight. 25–29.9: Overweight. 30 and above: Obese. These are WHO guidelines.
- Is BMI accurate?
- BMI is a screening tool, not a diagnostic measure. It does not account for muscle mass, bone density, age, or sex. Consult a healthcare professional for a full assessment.
- Is my data sent anywhere?
- No. All calculations run in your browser.
Understanding BMI: What It Measures, Its Limitations, and Alternatives
What BMI actually measures, why it is a screening tool not a diagnosis, its known limitations (muscle mass, ethnicity), and what to use alongside it.