Why use our BMI calculator?
Your body mass index (BMI) can be a good indicator of whether you’re a healthy weight. And you can use our BMI calculator to find out what yours is.
Having a BMI that’s higher than your healthy weight range can increase your risk of serious health problems like heart disease or type 2 diabetes. And a BMI that’s below your healthy weight range can affect your health too.
How does it work?
Simply put in a few details about yourself, including height and weight, and the calculator will use it to work out your BMI.
However, the BMI calculator isn't suitable for everyone. If you're under 18, pregnant, have a condition that affects your height or been diagnosed with an eating disorder, you shouldn't use it.
You can find out more about who can use the calculator on the NHS site.
BMI calculator
Body mass index (BMI) is a way to measure if you're a healthy weight for your height. You can use our simple BMI calculator, which is only suitable for adults, to work out yours.
Your body mass index (BMI) result is:
Your result suggests you are .
A healthy weight for your height is between:
Health Insurance
Our health insurance comes with added wellbeing benefits - helping you manage your BMI and live well today.Having a BMI that sits above your healthy weight range can bump up your risk of serious health problems like heart disease or Type 2 diabetes. And a BMI that puts you below your healthy weight range can disrupt your health too.
You can use the BMI result you got today as a first step to either jumping into new lifestyle changes or sparking a conversation with your GP.
Changing your BMI
Whatever BMI result you’ve received, a healthy lifestyle featuring a balanced diet and exercise can help you improve your current weight and BMI or, if you’re already a healthy weight, keep it at that sweet spot.
You can find information about managing your weight on the NHS website.
Why BMI isn’t always reliable
BMI might not be the best measure for everyone, because it can’t see the difference between fat, muscle and bone.
This means:
- Athletes or people with a lot of muscle may get an ‘overweight’ or ‘obese’ reading, even though their body fat is actually low.
- Older people may get a ‘healthy weight’ result even if they have too much body fat because they’ve lost muscle as they’ve aged.
Pregnancy will also affect a woman's BMI result. As their baby grows, they’ll gain weight, which will cause their BMI to go up.
How do you calculate BMI?
Once you’ve put your details in, the calculator divides your weight in kilograms and height in metres squared to work out your BMI. It then gives you a result to one decimal place.
Here’s how it works in practice Footnote [1].
Alex weighs 70kg (around 11 stone) and is 1.70m tall (around 5 ft 7). So the calculations would look like this:
- We square their height in metres, which would be 1.70 x 1.70 = 2.89
- Then, we take that number and divide their weight by it
- Dividing their weight in kilograms would give us 70 ÷ 2.89 = 24.22.
So, Alex’s result would be 24.2.
The limitations of BMI
For most people, BMI is a good indicator of if they’re a healthy weight. But it’s just one measure of health, and isn’t always accurate.
It can only measure if you’re carrying too much weight, not too much fat. So, it could give you a high BMI without much fat. Because it can’t tell the difference between them, it could class someone who has a lot of muscle as overweight or obese, despite having low body fat.
How we can help
We’re here to help you look after your health. That’s why our health insurance comes with a range of support, including access to wellbeing services that could help you manage your weight and BMI.
Here’s what you could get:
- Discounts at over 4,500 health and fitness clubs nationwide, online workouts, and a variety of products and services with Get Active^
- A 12-week programme covering important health topics such as diet, exercise, and weight lost with MyHealthCounts. And it could help you save money the next time you renew
- Unlimited video consultations with an NHS-registered private GP to talk about any health worries or advice for managing your weight with Aviva Digital GP^
- A range of top tips, guides, and general advice for looking after your health with our health and wellbeing articles.
^These services aren’t written into your contract, which means they could be changed or removed at any time.
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