BMI Calculator
Enter your height and weight to estimate your body mass index (BMI) and see which general category it falls in.
BMI Calculator
How to use
- Choose your units: feet/inches and pounds, or centimeters and kilograms.
- Enter your height and your current weight.
- Click Calculate BMI and read your value and category below the button.
What the number means
BMI is weight relative to height: weight in kilograms divided by height in meters squared. The common adult categories are underweight (below 18.5), healthy weight (18.5 to 24.9), overweight (25 to 29.9), and obesity (30 and above). It is a quick screening number, useful for spotting broad trends in a population and as one starting point in a personal health conversation.
What BMI does not measure
BMI does not measure body composition. It cannot tell muscle from fat, where fat is carried, or how fit someone is. A muscular person can score high while carrying little body fat, and an older adult can score in the healthy range while having lost muscle. That is why BMI should never be read alone: waist size, activity level, eating patterns, sleep, and a professional's assessment all add context that one number cannot.
Healthy next steps
If your result surprises you, treat it as a prompt for a general check-in, not a verdict. Regular movement you enjoy, balanced meals, enough sleep, and gradual changes tend to help more than crash approaches. For a personal plan, or if you have any health condition, talk to a healthcare professional first.
Frequently Asked Questions
What is a healthy BMI?
For most adults, a BMI from 18.5 to 24.9 is described as the healthy weight range. It is a general guide, not a personal target set for you.
Can BMI be wrong?
Yes, often for individuals. BMI ignores muscle mass, bone structure, age-related muscle loss, and fat distribution, so two people with the same BMI can have very different body composition.
Is BMI different for children?
Yes. Children's BMI is compared against age- and sex-based growth charts, not adult cutoffs, so this calculator is intended for adults.
How often should I check BMI?
There is no need to check daily. Weight changes slowly, so checking every few weeks, under similar conditions, gives a clearer trend.
Should I act on my BMI alone?
No. Use it as one data point alongside how you feel, your activity, and professional advice, especially before changing your diet or exercise routine.
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