What's your BMI?

Body frames vary and it's difficult for any simple measurement to work out a person's frame. It's more accurate to recommend a weight range, rather than a specific weight for a given height.

To calculate your BMI select your correct height and weight and let the BMI calculator do the rest.

BMI will vary slightly according to gender.

If you'd like to calculate your BMI yourself, follow these three steps.

1. Work out your height in metres and multiply the figure by itself.
2. Measure your weight in kilograms
3. Divide the weight by the height squared (ie. the answer to Q1). For example, you might be 1.6m (5ft 3in) tall and weigh 65kg (10st 3lb). The calculation would then be:

1.6 x 1.6 = 2.56. BMI would be 65 divided by 2.56 = 25.39.

Waist measurement

BMI alone is not a good guide to who is at most risk of obesity and cardiovascular disease.

Instead, waist circumference may be a much more accurate measure of future health problems because what matters is where you carry your excess kilos/pounds.

People who are an apple shape - they store fat around their midriff - are far more likely to develop heart disease and diabetes than those who are a pear shape or more diffusely plump.

A waist circumference greater than 80cm (32in) for women and 94cm (37in) for men indicates increased risk, while a measurement of more than 88cm (35in) for women and 102cm (40in) for men is particularly worrying.

Waist-hip ratio

An even better measurement of risk may be the ratio of your waist circumference (the narrowest point on your abdomen) to your hip circumference (the widest point).

A ratio of more than 1.0 for a man (in other words your waist is bigger than your hips) or 0.8 for a woman means you urgently need to reduce your weight and increase your levels of exercise.

Dr Rob Hicks last medically reviewed this article in October 2005.
First published in May 2001.