BMI Calculator
Calculate BMI from height and weight
BMI Categories
| Category | BMI Range |
|---|---|
| Underweight | 0 – 18.5 |
| Normal | 18.5 – 25 |
| Overweight | 25 – 30 |
| Obese (Class I) | 30 – 35 |
| Obese (Class II) | 35 – 40 |
| Obese (Class III) | 40 – 45 |
| Obese (Class III+) | 45+ |
* BMI is a rough indicator based on height and weight only. It does not account for muscle mass, body fat percentage, or age. Consult a doctor for health assessments.
How BMI is calculated and interpreted
BMI (Body Mass Index) is weight in kilograms divided by height in metres squared, and is widely used as a rough indicator of underweight or overweight. Just enter your height and weight to see the BMI value and category. The WHO classifies under 18.5 as underweight, 18.5–25 as normal, 25–30 as overweight, and 30+ as obese.
The calculation runs entirely in your browser and your height and weight are never sent anywhere. BMI is only a guide and does not reflect muscle mass or body fat, so consult a medical professional for an accurate assessment.
Frequently asked questions
- What is the BMI formula?
- BMI = weight (kg) ÷ (height (m) × height (m)). For example, 170 cm and 65 kg gives 65 ÷ (1.7 × 1.7) ≈ 22.5.
- What is an ideal BMI?
- A BMI around 22 is statistically associated with lower disease risk, but individuals vary, so treat it as a guide only.
- Are my height and weight stored?
- No. The calculation stays in your browser and your personal figures are never transmitted or saved.