What BMI tells you — and what it does not
BMI estimates body weight relative to height. It is a simple screening number, not a full health diagnosis. Muscle mass, age, sex and medical history also matter. Athletes may show a higher BMI without excess fat.
Metric vs imperial BMI calculation
Choose the unit system you prefer, enter weight and height, and get an instant result. Use the same units consistently if you track changes over time.
- Fitness and wellness check-ins
- Nutrition coaching baselines
- Personal health journals
- Quick screening before a doctor visit
Privacy-first health tools
Height and weight are sensitive. This BMI calculator runs locally in your browser — we do not upload or store your measurements. Treat results as informational and consult a clinician for medical advice.
