Toolzaio BMI Calculator
Enter your height and weight and see your body mass index straight away, in metric or imperial units.
BMI is a rough guide, not a diagnosis. It does not tell muscle from fat, so athletes can score high while being fit, and it works less well for children, older people and during pregnancy. For real health questions, talk to a doctor.
How it works
Body mass index is your weight in kilograms divided by your height in metres, squared. A person who weighs 70 kg and stands 1.75 m tall has a BMI of 70 ÷ (1.75 × 1.75), which comes to 22.9. The calculator converts feet, inches and pounds into the same maths when you pick imperial units.
For adults, the standard reading of the result is: below 18.5 is classed as underweight, 18.5 to 24.9 as a healthy weight, 25 to 29.9 as overweight, and 30 or above as obese. These bands come from the World Health Organization and are used by doctors as a first, quick screen. The calculator also shows the healthy weight range for your height, which is often more useful than the single number.
Questions people ask
Is BMI accurate?
It is a useful first check for most adults, but it is a blunt tool. It cannot see where weight sits on your body or how much of it is muscle. Treat it as one signal among many, not a verdict on your health.
What is a healthy BMI?
For adults, 18.5 to 24.9 is the band classed as healthy. A result a little outside the band is common and is not on its own a reason to worry.
Does BMI work for children?
No. Children and teenagers are measured against growth charts that account for age and sex, because their bodies are still changing. This calculator uses the adult bands.
Why does my healthy weight range look wide?
Because healthy bodies genuinely vary. The range for a given height can span 15 kg or more, covering different builds and levels of muscle. Anywhere inside it counts as the healthy band.
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