How to use the BMI Calculator
Fill in the fields above and the result appears straight away. Everything runs in your browser, so nothing you type is uploaded.
The formula
BMI = kg ÷ m².
Examples
- 70 kg, 175 cm
Estimated BMI: 22.9 Category: Healthy weight
- 90 kg, 180 cm
Estimated BMI: 27.8 Category: Overweight
- 55 kg, 165 cm
Estimated BMI: 20.2 Category: Healthy weight
Limitations and assumptions
BMI is a screening measure only and does not account for age, pregnancy, body composition or individual health.
Frequently asked questions
How is BMI calculated?
Weight in kilograms divided by height in metres squared.
What are the BMI categories?
For most adults: under 18.5 underweight, 18.5 to 24.9 healthy weight, 25 to 29.9 overweight and 30 or above obesity.
What does BMI miss?
It ignores muscle mass, fat distribution, age and ethnicity, so a muscular person can score high without excess fat.
Is it suitable for children?
No. Children use age- and sex-specific percentile charts.