BMI calculator — and what it really tells you
Get your number, then get the honest context most BMI charts leave out.
BMI is everywhere — on charts, in apps, at the doctor's office. It can be a useful quick screen, but it was never meant to judge an individual's health, and it definitely doesn't measure your worth. Here's the number, with the context.
The honest version: BMI is a quick population screen — weight relative to height. It can't tell muscle from fat, can't see where you carry weight, and isn't a diagnosis or a measure of your health or worth. Use it as a rough flag, alongside measures like waist-to-hip ratio and how you feel.
Calculate your BMI
BMI
A rough screening tool — it can't tell muscle from fat. Please take it with a grain of salt.
Let’s look at the fuller picture together.
What BMI misses
- Muscle vs. fat. It weighs them the same, so athletes can read as “overweight.”
- Where you carry it. Belly fat and hip fat carry different risk; BMI can't tell.
- Who you are. Its meaning shifts with age, sex, and ethnicity — it's a population average.
- How you actually are. Strength, energy, blood pressure, and labs say far more.
For a fuller picture, pair it with your waist-to-hip ratio, which captures where you store fat — often more health-relevant than weight alone.
Common questions
What is BMI and how is it calculated?
Body mass index (BMI) is your weight relative to your height: weight in kilograms divided by height in meters squared (or 703 × pounds ÷ inches²). It was designed as a quick population-level screening tool, not an individual diagnosis.
What is a healthy BMI range?
For adults, the standard categories are: under 18.5 underweight, 18.5–24.9 “normal,” 25–29.9 overweight, and 30 or above obese. These are general population cutoffs — useful as a rough flag, not a personal verdict.
Is BMI accurate?
BMI is a blunt instrument. It cannot tell muscle from fat, so a muscular person can read as “overweight” while someone at a “normal” BMI may carry excess fat. It also ignores where you store fat and varies in meaning across age, sex, and ethnicity. Treat it as one rough data point among many.
What’s a better measure than BMI?
No single number captures health, but waist measurement and waist-to-hip ratio add useful information about fat distribution, and things like strength, energy, blood pressure, and lab work tell you far more. How you feel and function matters most of all.
This is general education, not medical advice or a diagnosis. Talk with your healthcare provider about what these numbers mean for you.