BMI Calculator
Check your body mass index and healthy weight range.
Reviewed by Zerunio’s medical team
Body mass index (BMI) compares your weight to your height to flag whether you're in a healthy range. It's a quick screen, not a diagnosis – it doesn't measure body fat or muscle directly.
This tool gives general estimates for education only – it is not medical advice. Talk to a clinician about your health.
Frequently asked questions
What is a healthy BMI?
For most adults, a BMI of 18.5 to 24.9 is considered a healthy weight. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above falls in the obesity range.
Is BMI accurate for everyone?
No. BMI doesn't tell muscle from fat, so very muscular people can read as 'overweight', and it can under-read risk in older adults. It's a screening tool – your doctor looks at the whole picture.
Is BMI different for men and women?
The formula and the healthy-range cut-offs are the same for both – that's why this tool doesn't ask your sex. At the same BMI women naturally carry a bit more body fat than men, but the number and category don't change.
Does BMI work for children?
Not directly. Children and teens use age- and sex-specific BMI percentiles, not the adult categories here.
How can I get to a healthy weight?
Small, steady changes work best – more everyday movement, more vegetables and fibre, fewer ultra-processed foods, and enough sleep. A doctor or dietitian can tailor a plan.