BMI Calculator
Calculate your Body Mass Index (BMI) from height and weight, in metric or imperial units.
| Underweight | < 18.5 |
| Normal | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obese | ≥ 30 |
Formula & methodology
Metric: BMI = weight(kg) / height(m)². Imperial: BMI = 703 × weight(lb) / height(in)².
Uses the World Health Organization adult classification: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese.
Worked example
- 70 kg, 175 cm → BMI 22.9 — Normal weight
- 154 lb, 69 in → BMI 22.7 — Normal weight
Frequently asked questions
Is BMI accurate for everyone?
BMI is a simple screening tool and does not distinguish muscle from fat. Athletes, pregnant people, children and the elderly may need other measures.
What is a healthy BMI?
For most adults a BMI between 18.5 and 24.9 is considered the normal range.
Privacy
All processing happens locally in your browser. Your data is never uploaded.
Disclaimer: This calculator is for general information only and is not medical advice. Consult a healthcare professional about your health.