BMI Calculator – Body Mass Index
Calculate your Body Mass Index (BMI) instantly. Supports metric (cm/kg) and imperial (ft/lb) units with result category.
How to Use
- 1
Select metric or imperial units
- 2
Enter your height and weight
- 3
Click "Calculate BMI" to see your result and category
Frequently Asked Questions
What is BMI?
BMI (Body Mass Index) is a measure of body fat based on height and weight. It's used as a general health indicator.
What is a healthy BMI?
A BMI between 18.5 and 24.9 is considered normal weight for adults.
Is BMI accurate for everyone?
BMI is a screening tool, not a diagnostic one. It may not accurately reflect health for athletes, elderly, or children.
Is my data stored?
No — all calculations happen locally in your browser. No data is sent to any server.
How this is calculated
BMI = weight (kg) / height (m)²
Where
- weight in kilograms
- height in metres, i.e. centimetres ÷ 100
What this assumes
- Categories follow the WHO cut-offs used on this page: under 18.5 underweight, 18.5 to under 25 normal, 25 to under 30 overweight, 30 and above obese.
- BMI does not distinguish muscle from fat and is not meaningful for children, pregnancy or athletes.
Source: World Health Organization, body mass index classification for adults
This is a reference value, not a medical assessment.
What the BMI calculator tells you
A BMI (Body Mass Index) calculator estimates whether your weight is in a healthy range for your height. You enter height and weight and it returns a single number plus the category it falls into, from underweight to obese.
BMI is a quick screening figure, not a full health assessment — it does not account for muscle, build or age.
Good to know
- Works with both metric and imperial units.
- Useful as a starting point in a fitness or weight journey.
- Always discuss real health decisions with a professional.
- Planning intake too? Try the calorie calculator or check your age.
Your health data stays with you
Your numbers are calculated in your browser and never stored, so the tool is completely confidential.