BMI Calculator
Work out your Body Mass Index (BMI) from your height and weight, in either metric or imperial units, and see which healthy-weight category you fall into.
Enter your measurements
Result
Enter your height and weight to calculate your BMI.
Understanding your BMI
BMI compares your weight to your height. A result between 18.5 and 24.9 is generally considered a healthy range for adults. BMI is a screening tool only — it does not distinguish between muscle and fat, and it may not suit athletes, pregnant people or children.
- Under 18.5 — underweight.
- 18.5 to 24.9 — healthy weight.
- 25 to 29.9 — overweight. 30+ — obese.
This tool is for general information and is not medical advice. Speak to a healthcare professional about your individual health.
Frequently asked questions about BMI
What is a healthy BMI range?
For most adults a BMI between 18.5 and 24.9 is considered a healthy weight. Below 18.5 is underweight, 25 to 29.9 is overweight and 30 or above is classed as obese.
Is BMI accurate for everyone?
No. BMI does not distinguish muscle from fat, so it can label muscular athletes as overweight, and it is not designed for children, pregnant people or older adults. Treat it as a general screening guide, not a diagnosis.
How is BMI measured in metric and imperial units?
In metric units BMI equals weight in kilograms divided by height in metres squared. In imperial units it is 703 times weight in pounds divided by height in inches squared.