Diet, Exercise & Lifestyle: BMI Calculator
Body Mass Index (BMI) Calculator.
Choose either Imperial or Metric units and fill in your details to see the results below.
- If your BMI is less than 18.4, you're underweight for your height.
- If your BMI is between 18.5 and 24.9, you're an ideal weight for your height.
- If your BMI is between 25 and 29.9, you're overweight for your height.
- If your BMI is between 30 and 39.9, you're obese.
- If your BMI is over 40, you're very obese.
If you have a BMI of over 25, you need to think about losing weight because you have an increased risk of developing serious health problems, such as heart disease, diabetes, and several forms of cancer.
If your BMI is over 30, you need to make some immediate changes to your lifestyle in order to lose weight. NHS Direct can provide you with advice about how to lose weight safely, but you should also make an appointment to see your GP.
Page last updated: 6 December 2011