BMI Calculator

Calculate your BMI using metric or imperial units and see which weight category you fall into, with a visual range indicator.

Metric (cm / kg)

I am cm tall and weigh kg

Imperial (ft / lbs)

I am ft in and weigh lbs

Understanding BMI

BMI is calculated by dividing your weight in kilograms by the square of your height in metres:

BMI = weight (kg) ÷ height² (m)

While BMI is a widely used screening tool, it does not directly measure body fat. Factors like muscle mass, bone density, age, and ethnicity can affect interpretation. Always consult a healthcare professional for a full health assessment.

Healthy Weight Range

For a given height, the healthy weight range corresponds to a BMI between 18.5 and 24.9. The calculator shows your healthy weight range after computing your BMI.

Frequently Asked Questions

Body Mass Index (BMI) is a measure that uses your height and weight to estimate whether you are in a healthy weight range. BMI = weight (kg) ÷ height² (m).

Underweight: below 18.5 | Normal weight: 18.5–24.9 | Overweight: 25–29.9 | Obese (Class I): 30–34.9 | Obese (Class II): 35–39.9 | Severely obese (Class III): 40 and above.

BMI is a useful screening tool, but it has limitations. It does not distinguish between muscle and fat, so athletes may show a high BMI despite low body fat. Age, sex, and ethnicity also affect the interpretation.

For most adults, a BMI between 18.5 and 24.9 is considered healthy. However, always consult a healthcare professional for personalised advice.

BMI = (weight in lbs × 703) ÷ (height in inches)². This calculator handles the conversion automatically.