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BMI (Body Mass Index)

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Your Body Mass Index or BMI is a good way for you to check if you’re a healthy weight. For adults BMI is used to measure if you’re a healthy weight for your height meaning the calculation takes into account that all people are different shapes and sizes.

What is my BMI?

You can work out your BMI by using a calculator, chart or using the formula below. To calculate your BMI, you'll need to know your weight in kilos and your height in metres, then follow the example below:

Step one: Multiply your height in metres by itself, eg 1.7 x 1.7= 2.89

Step two: Divide your weight in Kilos by this figure, e.g 80 ÷ 2.89 = 27.7

Step three: For this example 27.7 is your BMI

You can also use this BMI chart to calculate your BMI:

BMI table

What does my BMI score mean?

Below 18.5:

A score this low means that you may be underweight. There are a number of possible reasons for this and your GP can help you achieve a healthy weight. You can also read our weight gain article to find out what you can eat to gain weight healthily.

18.5 - 24.9:

This is a healthy BMI range, and it shows that you're a healthy weight for your height. Make sure that you are eating your 5-portions of fruit and vegetables a day and drink plenty of water.

25 or more:

Your BMI is above the ideal range and this score means you may be overweight. This means that you're heavier than is healthy for someone of your height. Carrying excess weight can put you at increased risk of heart disease, stroke and type 2 diabetes. To find out how you can healthily lose weight, read our weight loss article here.

30 or more:

A BMI above 30 is classified as obese. Being obese puts you at a raised risk of health problems such as heart disease, stroke and type 2 diabetes. Losing weight will help to improve your health and well-being. Read our top 12 tips for weight loss today.

Can a weight scale work out my BMI?

There are digital scales that you can use at home or even at your local gym that can calculate your BMI amongst other health stats. The LloydsPharmacy body analysis scale can read your body fat and muscle percentage as well as work out your Body Mass Index. Regularly using the scale can help you see any changes in your BMI easily and accurately.

Find out more about the best scales for weight loss in our blog.

Is there a BMI calculator?

The NHS BMI calculator allows you to check your BMI and understand your result. Simply select whether you’re an adult or child then enter your height, weight, age, sex, ethnic group (optional) and activity level for personalised BMI results. The calculator will explain your BMI result as well as give you tips and advice around your weight.

Please bear in mind that BMI can’t tell the difference between fat, muscle and bone. The adult BMI also doesn’t consider your age, gender or muscle mass. If you’re pregnant or have an eating disorder you shouldn’t use the BMI calculator.

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