You’ll need to tell the calculator your age, gender, activity level, height and weight.
This will then give you a number, which is your BMI.
These typically range from 18.5 to around 40.
A BMI of under 18.5 suggests you are in the underweight category, 18.5-24.9 is a healthy weight, 25-29.9 is considered the overweight category, 30-39.9 is obese, and anything over 40 tends to mean the person is morbidly, or clinically obese and should seek help from a professional.
It’s important to remember that your BMI result is not the perfect measure of your overall health.