Enter your height and weight to see your body mass index, the adult category it falls in, and the weight range for your height.
This tool gives general information, not medical advice. Talk to a doctor or qualified professional about your personal needs.
What your BMI result means
BMI is a simple way to compare your weight with your height. For adults, the World Health Organization groups the result into four bands: under 18.5, 18.5 to 24.9, 25 to 29.9 and 30 or above. The calculator also shows the range of weights that would put you between 18.5 and 24.9 at your height.
What BMI cannot tell you
BMI is a screening number, not a diagnosis. It does not measure body fat, muscle, bone or where weight sits on your body. It can be less reliable for people who are very muscular, older adults, and anyone who is pregnant. Two people with the same BMI can have very different health, so please do not use one number to judge yourself.
Look at the bigger picture
How you eat, move, sleep and manage stress says more about your health than a single score. If you want somewhere gentle to start, building a little strength at home with our beginner strength plan, or taking regular walks, is a good habit whatever your BMI. Eating more fibre, as covered in our fibermaxxing guide, can also help you feel full and support your digestion.
When to talk to a doctor
Speak to a doctor or practice nurse if your BMI is outside the healthy range and you are worried, if your weight has changed a lot without a clear reason, or if you have a health condition. They can look at your whole health, not just one number, and advise on what is right for you.
Frequently Asked Questions
What is BMI?
BMI stands for body mass index. It is your weight in kilograms divided by your height in metres squared. It gives a quick screening number that doctors use alongside other checks.
What is a healthy BMI for adults?
The World Health Organization uses 18.5 to 24.9 as the healthy range for adults. Under 18.5 is below it, 25 to 29.9 is above it, and 30 or more is well above it. Some health bodies use different cut-offs for some ethnic groups.
Is BMI accurate?
It is only an estimate. BMI cannot tell fat from muscle, and it does not show where fat is carried on the body. A very muscular person can have a high BMI and still be healthy, and someone with a BMI in the healthy range can still have health risks.
Does BMI work for children and teenagers?
Not in the same way. For anyone under 18, BMI is compared with growth charts for their age and sex, so the adult categories do not apply. This calculator shows the number but no category if you enter an age under 18.
Does the calculator save my height and weight?
No. Everything is worked out in your browser. Nothing you type is sent to us or stored.
This tool gives general information, not medical advice. Talk to a doctor or qualified professional about your personal needs.
