Do you know what a BMI calculator tells you? Do you understand your Body Mass Index? For these and more questions about our BMI Calculator, read on with our simple guide and then try it out below to see how you fare.

Using your input details, check the chart below to indicate the value of your body mass index and whether you are underweight, of normal weight, overweight or obese. Your body mass index is an objective scientific measure, that uses your height and weight.

Using our BMI calculator allows you to work out your body mass index by dividing your weight in kilograms by the square of your height in meters (BMI=kg/m2).

Body mass index should only be a guide, and will not be at all accurate in some circumstances. A trained athlete, or someone with very muscular body will often show on a BMI scale as obese.

If you have any concerns about your weight, weightlossforgood.co.uk suggests that you contact your GP or medical practitioner and run some proper scientific tests.

If you need to convert your height into meters use the Height Convertor provided

Calculate your BMI

Height (in.)	Weight (lbs.)

Your BMI is :

If your BMI is below 18.5:
This indicates a lean BMI, indicating low body fat. In certain circumstances this can be desirable (e.g. an athlete). However, a low BMI can indicate that your weight may be too low which may lower your immunity to disease. If your BMI and body weight are low, you should consider gaining increased muscle mass through a healthy diet and exercise program.

If your BMI is between 18.5 and 24.9:
A BMI in this range indicates a healthy level of body fat. A BMI percentage in this range is associated with longevity, and a low incidence of serious illness. Studies have shown that this is the level that most people find aesthetically pleasing.

If your BMI is between 25 and 29.9:
A BMI in this range is considered to be overweight, and having an increased risk of associated disease. Ideally if you are in this range you should find ways to lower your weight. Start by changing to a healthy diet and undertake an exercise program.

If your BMI is between 30 and 39:
We have now reached the obesity range. It is essential that a lifestyle change is undertaken. A change to a healthy diet and regular exercise is essential. Why not check out Exercise At Home for a few exercises to try. If an individual is in this range and has a waist size greater than or equal to 40 in. (men) or 35 in. (women) then there is a very high associated risk of disease.

If your BMI is over 40:
This indicates an individual suffering from extreme obesity, and is in a very unhealthy condition. The excess body fat will put the individual at risk of heart disease, diabetes, high blood pressure, gall bladder disease and some cancers. It is definitely time to change to a healthy diet and undertake a fitness program.

Click here to view the BMI index chart.