BMI Calculator
Calculate your Body Mass Index (BMI) and assess potential health risks
Additional Information and Definitions
Weight
Enter your weight in kilograms (metric) or pounds (imperial)
Height
Enter your height in centimetres (metric) or inches (imperial)
Unit System
Choose between metric (centimetres/kilograms) or imperial (inches/pounds) measurements
Health Risk Assessment
Get instant BMI results and personalised health insights based on your measurements
Loading
Understanding BMI and Health Risks
Learn about key BMI-related terms and their significance for your health:
Body Mass Index (BMI):
A numerical value calculated from your weight and height that provides a reliable indicator of body fatness for most people.
Underweight (BMI < 18.5):
Indicates insufficient body weight relative to height, which may signal nutritional deficiencies or other health issues.
Normal Weight (BMI 18.5-24.9):
Considered the healthy range associated with the lowest risk of weight-related health problems.
Overweight (BMI 25-29.9):
Indicates excess body weight relative to height, which may increase risk of certain health conditions.
Obese (BMI ≥ 30):
Indicates significant excess body weight, which substantially increases risk of serious health conditions.
5 Surprising Facts About BMI You Never Knew
While BMI is a widely used health indicator, there's more to this measurement than meets the eye.
1.The Origins of BMI
BMI was developed by Belgian mathematician Adolphe Quetelet in the 1830s. Originally called the Quetelet Index, it wasn't meant to measure individual body fat but to help the government estimate the degree of obesity of the general population.
2.BMI's Limitations
BMI doesn't distinguish between weight from muscle and weight from fat. This means athletes with high muscle mass might be classified as overweight or obese despite being in excellent health.
3.Cultural Variations
Different countries have different BMI thresholds. For example, Asian countries often use lower BMI cutoff points for overweight and obesity classifications due to higher health risks at lower BMI levels.
4.Height's Disproportionate Impact
The BMI formula (weight/height²) has been criticised because it can overestimate body fat in tall people and underestimate it in short people. This is because it squares height, giving it a disproportionate impact on the final number.
5.Historical Changes in 'Normal' BMI
What's considered a 'normal' BMI has changed over time. In 1998, the U.S. National Institutes of Health lowered the overweight threshold from 27.8 to 25, instantly categorising millions of people as overweight overnight.