BMI Calculator
Body Mass Index from your height and weight
Enter your height and weight to get your Body Mass Index (BMI) and where it falls — a quick screening of whether your weight is in a healthy range for your height.
What BMI means
BMI is weight relative to height. Standard categories: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese.
BMI is a rough screen, not a diagnosis — it doesn't distinguish muscle from fat. Talk to a doctor about your health.
Where BMI falls short
Because it uses only height and weight, BMI can over-estimate body fat in very muscular people and under-estimate it in older adults who've lost muscle. It also says nothing about where fat is stored — waist circumference and body-fat percentage often tell you more about health risk than BMI alone.
Use it as one signal
Think of BMI as a quick, free starting point rather than a verdict. Trends matter more than a single reading: tracking it over time, alongside measurements like waist size and how you feel and move, gives a fuller picture. For anything that concerns you, a clinician can interpret it in context.
BMI Calculator: frequently asked questions
Is BMI accurate?
It's a useful population-level screen but imperfect for very muscular or older individuals, since it can't tell muscle from fat.
What is a healthy BMI?
A BMI between 18.5 and 24.9 is generally considered the healthy range for most adults.
What is a healthy BMI for my age?
The standard 18.5–24.9 range applies to most adults regardless of age, though some research suggests slightly higher may be fine for older adults. Children and teens use age- and sex-specific percentile charts instead.